How water heater thermostats works
More detail: Electric water heaterA bi-metal switch is two different metals sandwiched together. Metal expands when heated, except one metal expands differently than other metal, causing a deformation or bend. Inside electric water heater thermostat, the bending metal opens and closes a mechanical switch.Typical household non-simultaneous water heater has 2 heating elements called upper and lower elements. Elements are controlled by upper and lower thermostats. Each element is connected to a thermostat. Thermostats read temperature through side of tank wall and turn elements ON and OFF. Residential water heater thermostats can be manually set to temperatures between90�Fto 150 �F. Commercial water heater thermostats120-180 �F.How to adjust thermostatsHow to replace thermostat on electric water heater Higher thermostat settings use more electricity.Both elements on ordinary residential water heater are never ON at same time unless specific wiring is changed.How to wire thermostats Upper thermostat is main controller. Upper thermostat turns on upper element until top 2/3 of tank reaches temperature setting. After top of tank is heated, upper thermostat turns-off upper element and sends power to lower thermostat which turns on lower element. Lower element runs until tank reaches temperature setting.Lower element turns on-and-off during standby hours to keep tank temperature at thermostat set point. | See LargerSome thermostats, the L2 and T1 screws are empty slot or rivet since wires do not connect to either L2 or T1.Brands of thermostat vary slightly, screws are located differently, some numbers are slightly different, but basic concept is same from brand to brand. Water heater manuals available on-line. Label on side of tank shows watts and volts of appliance.Each thermostat comes with instruction sheet.When replacing thermostat, take digital photo of water heater and old thermostat to hardware store or plumbing store for quick identification.Thermostat must sit flat against tank wall so temperature reading is accurate and water heater is protected from overheating | More detail: Electric water heater thermostat operation sequence Residential water heaters can be wired 4 basic ways.Non-simultaneousfound in most residential water heaters.Plussimultaneous,redundant, andoff-peak. The key is knowing how a thermostat works.How to wire thermostatsDiagram on left illustrates basic non-simultaneous thermostat function. This thermostat is found on 240 Volt water heaters that have 2 elements. Check label on side of tank for voltage info.Figure volts, amps, wattsPower from breaker box connects to L1 and L3 screwssome thermostats, the screws are marked simply 1 and 3.Top half of thermostat is the ECO or energy cut offThe ECO is heat sensitive, so if temperature reaches dangerously high 150-180 �F, then ECO trips and water heater no longer has power. This prevents water heater explosion.Viewing the diagram, power from L1 and L3 pass through ECO red reset and go to L2 and L4 screws.After power passes through ECO, it is available for heating water. To control heating, power arrives at the thermostat which begins at T1 screw.Inside the thermostat a bi-metal switch. Two different metals are fused together. Each metal expands differently when heat is applied. Since the two metals are joined, the metal that expands most causes the bi-metal switch to bend. The bending action opens and closes the switch.In the diagram, the bi-metal switch is connected to T1. When temperature inside tank is cool, the bi-metal switch rests against T2 so power travels from T1 to T2, and then on to the upper heating element. When temperature inside tank is hot, the bi-metal switch disengages from T2 and clicks over to T4. When this happens, T1 sends power to T4, so the upper heating element is turned off and power travels to lower element and thermostat through the T4 screw.In a 240 Volt water heater, elements must receive power from 2 hot leads. The diagram shows the hot leads at L1 and L3 screws. In the description above, power from one hot lead was switched between T2 and T4. From there, power traveled to the elements but the circuit was not yet complete. To complete the 240 circuit, each element must connect back to the L4 screw.See complete circuit diagram below. |
Water Heater Thermostat How To Guide
If you are seeking for information on water heater thermostats, you can find it all right here. Instructions on how to test or replace a thermostat. How to check the limit switch, modify the temperature, and more are all covered in this article.
How a thermostat works
A water heater thermostat is a very simple piece of equipment. They are controlled by a bi-metal switch, which is positioned on the rear of the thermostat unit. After reaching a particular temperature, the bi medal disk will pop in or out, depending on which case it is in, and connect or disconnect the power supply to the heating element. This bi-metal disk is the source of the clicking sound you hear when the temperature is increased or decreased.
Thermostat and limit switch
Aduel element 240 volt storage water heater thermostats are shown in this photograph. On the left is the upperor primary thermostat, which is the upperor major thermostat. The loweror secondary thermostat is located on the right-hand side of the thermostat. In the upper thermostat, there is a limit switch fixed on it. Limit switch and thermostat have been detached so that you can see them both individually in the picture above. This limit switch (at the top of the photo) has a red reset button on the side.
- The topleft terminal of the thermostat is where power is supplied.
- When the thermostat has been satisfied, electricity is sent to the top right terminal and subsequently to the lower thermostat.
- The upper thermostat sends power to the top terminal, which is connected to the battery.
- The thermostat to the right is intended for use with a single element water heater.
- As you can see, the single elementthermostat has only two terminals on the right side of the device.
- When the thermostat indicates that heat is required, electricity is sent to the lower terminal, which activates the lower element.
Water heater thermostat buyers guide
Aduel element 240 volt storage water heater thermostats are seen in this photo. Lower or principal thermostat is represented by the thermostat on the left. This is the loweror secondary thermostat, which may be seen on the right. Using a limit switch, the top thermostat is secured. Limit switch and thermostat have been separated so that you can view them both individually in the picture below. The red reset button on this limit switch (at the top of the photo) is easily accessible. It is obvious that this thermostat is quite straightforward.
A power signal is provided to the bottom left terminal when a heat signal is received from the thermostat, which then energizes the top element When the thermostat has been satisfied, electricity is sent to the top right terminal and subsequently to the bottom thermostat terminal.
The upper thermostat sends power to the top terminal, which is then connected to the rest of the device.
The thermostat to the right is intended for use with a single element water heater.
There are just two terminals on the right side of this single elementthermostat, as you can see. Electrical energy is delivered to the top terminal by the main power source. In response to the thermostat’s request for heat, power is sent to the lower terminal, which then powers up the lower element.
Related links
Check the thermostat’s performance. How to inspect a thermostat when the electricity is turned off. Thermostats may be examined with and without the electricity turned on. If you are comfortable working with the electricity turned on, you may check the voltage at the element to determine if the thermostat is functioning properly. To replace a thermostat, follow these steps: This step-by-step instruction will walk you through the process of replacing a thermostat. There are no specialized tools necessary.
How to reactivate the limit switch on your water heater.
Is there a recommended temperature for your water heater?
Troubleshooting the Thermostat on a Hot Water Heater
It is possible to have one or two thermostats on an electric water heater, depending on how many gallons are in the tank. The thermostats govern the temperature of the water. The thermostats function by activating the heating components when the water temperature drops below a predetermined level. If any of the thermostats fail to operate, you will be unable to obtain hot water, or the water may begin to heat to dangerously high degrees, resulting in burns.
Electric Water Heater Problem
An electric water heater is made up of one or two thermostats that regulate the temperature of the water, depending on the gallon capacity of the tank installed. The thermostats function by activating the heating components when the water temperature drops below a preset threshold. It is possible that you may be unable to obtain hot water or that the water will begin to heat to dangerously high degrees if any of the thermostats fail to operate properly.
Learning How to Fix Hot Water Elements and Thermostats
Thermostats are used by all types of water heaters. It is not a time-consuming process, but it does need dealing with potentially lethal high-voltage equipment. Prior to operating with a heating equipment, it is usually a good idea to turn off the main electricity. If you intend to repair your water heater on your own, the following steps will help you through the process:
- To begin, switch off the water heater’s breaker, which may be found within the breaker panel. Locate the screws that are holding the electric access panel to the water heater in place
- Then, remove the screws and open the panel to provide access to the water heater. You will be able to examine the electrical wiring that is responsible for the water heater. Disconnect the power slowly and with extreme caution. By stopping the flashing of the voltage sensor, you will be able to determine if the electricity has been interrupted
- You may now remove the access panel and expose the insulation beneath it. Remove the plastic protection cover from the thermostat and assign a number to each thermostat screw if there is a wire linked to it
- Also, remove the plastic protector cover from the thermostat. Wrap a strip of painter’s tape over each wire that is attached to the screw while carefully holding each wire in your hands. On the tape, write the thermostat crew number that corresponds to the cassette. The wires will be removed from behind the thermostat and placed on a piece of tape, which will be labeled “3.” Now gently unscrew the screw in front of the thermostat and carefully take the wires from behind it. Afterwards, remove the thermostat’s mounting clamps and carefully take the thermostat away from the heater. Take this thermostat with you and look for an appropriate replacement. Bring the replacement thermostat, which should be identical to your old thermostat, home
- Number the thermostat screws on the new device in the same manner as you did on the old device. Check to ensure that the numbers on the old thermostat match the numbers on the new thermostat
- Precious time should be spent carefully removing wires from the water heater and attaching them to the appropriate screws on the thermostat
- Reattach the plastic shield to the thermostat and check to see that the red colored ‘Reset’ button can be seen through the hole in the cover when the lid is closed. Last but not least, switch on the breaker and click the reset button to bring the temperature of the thermostat down to 120 degrees Fahrenheit from its previous setting. Replace the access panel as well as the insulation panel. If there is another thermostat hidden behind a top access panel, use the same procedure as above.
Before you begin working on your system, double-check that you have all of the necessary tools, such as a screwdriver, painter’s tape, gloves, and a replacement thermostat, on hand. Ensure that the electricity has been turned off as well so that you may work with the system without the risk of receiving an electric shock from the system. If you require further assistance, please do not hesitate to contact Service Champions Heating & Air Conditioning for assistance. It is possible to have one or two thermostats on an electric water heater, depending on how many gallons are in the tank.
The thermostats function by activating the heating components when the water temperature drops below a predetermined level. If any of the thermostats fail to operate, you will be unable to obtain hot water, or the water may begin to heat to dangerously high degrees, resulting in burns.
Electric Water Heater Problem
If your water heater is malfunctioning, you will notice that it warms water too slowly, does not create any hot water at all, produces hot water of worse quality than normal, or heats water to dangerously high temperatures. It is possible that the problem is with the thermostat of your heating equipment, which may be readily resolved by performing a simple repair or replacing the heating components.
Learning How to Fix Hot Water Elements and Thermostats
Thermostats are used by all types of water heaters. It is not a time-consuming process, but it does need dealing with potentially lethal high-voltage equipment. Prior to operating with a heating equipment, it is usually a good idea to turn off the main electricity. If you intend to repair your water heater on your own, the following steps will help you through the process:
- To begin, switch off the water heater’s breaker, which may be found within the breaker panel. Locate the screws that are holding the electric access panel to the water heater in place
- Then, remove the screws and open the panel to provide access to the water heater. You will be able to examine the electrical wiring that is responsible for the water heater. Disconnect the power slowly and with extreme caution. By stopping the flashing of the voltage sensor, you will be able to determine if the electricity has been interrupted
- You may now remove the access panel and expose the insulation beneath it. Remove the plastic protection cover from the thermostat and assign a number to each thermostat screw if there is a wire linked to it
- Also, remove the plastic protector cover from the thermostat. Wrap a strip of painter’s tape over each wire that is attached to the screw while carefully holding each wire in your hands. On the tape, write the thermostat crew number that corresponds to the cassette. The wires will be removed from behind the thermostat and placed on a piece of tape, which will be labeled “3.” Now gently unscrew the screw in front of the thermostat and carefully take the wires from behind it. Afterwards, remove the thermostat’s mounting clamps and carefully take the thermostat away from the heater. Take this thermostat with you and look for an appropriate replacement. Bring the replacement thermostat, which should be identical to your old thermostat, home
- Number the thermostat screws on the new device in the same manner as you did on the old device. Check to ensure that the numbers on the old thermostat match the numbers on the new thermostat
- Precious time should be spent carefully removing wires from the water heater and attaching them to the appropriate screws on the thermostat
- Reattach the plastic shield to the thermostat and check to see that the red colored ‘Reset’ button can be seen through the hole in the cover when the lid is closed. Last but not least, switch on the breaker and click the reset button to bring the temperature of the thermostat down to 120 degrees Fahrenheit from its previous setting. Replace the access panel as well as the insulation panel. If there is another thermostat hidden behind a top access panel, use the same procedure as above.
Before you begin working on your system, double-check that you have all of the necessary tools, such as a screwdriver, painter’s tape, gloves, and a replacement thermostat, on hand. Ensure that the electricity has been turned off as well so that you may work with the system without the risk of receiving an electric shock from the system. If you require further assistance, please do not hesitate to contact Service Champions Heating & Air Conditioning for assistance.
Electric Hot Water Heater Thermostat
It goes without saying that the temperature of your hot water is a significant factor in your interest in electric water heater thermostats. In order to modify the water temperature, go to the thermostat and adjust it there. Most of the time, thermostats are activated when there is either too little or no hot water available to the household. The thermostats might be a contributing factor or the entire problem. Not sure if the thermostats are the source of the problem? See the page on ‘Electric Water Heater Troubleshooting’ for detailed explanations of all of the most frequent problems, as well as a list of resources for learning how to resolve them.
How Electric Water Heater Thermostats Work
An electric water heater thermostat regulates the temperature of the water heater by telling the heating components when to begin heating. The majority of electric hot water tanks are equipped with two elements and two thermostats. Neither the elements nor the heat exchanger heat up at the same time. The top element heats the water first, and then the lower element comes on to complete the heating cycle. The top thermostat serves as a link between the two other sections of the system. When the water in the top portion of the tank is sufficiently heated, the bottom thermostat is able to activate.
This occurs only when the top element has completed its heating cycle.
There is another possibility for your being here.
In order to modify the temperature of the water, you must first locate the thermostats in question. When compared to your furnace, these thermostats are a little more difficult to calibrate. There are a handful of things you must perform in order to make them visible.
Electric Water Heater Thermostat – Information
The top thermostat costs around $20 to $25, while the lower thermostat costs approximately $10 to $15. You would most likely have to pay roughly $100 in labor to get them installed.
How Hard Could It Be?
Replacing the thermostat on an electric water heater is not a very difficult task. You’re dealing with some really powerful energy, which raises the stakes in terms of safety.
- Level of Difficulty: A little bit of work
- Determined Handyman with a high level of skill
See the section under “How to Use This Site” for a definition of the words used in this section.
Check the Simple Things!
Before you replace the thermostats, try the reset buttons to see if they work. Each thermostat is equipped with one. When the power is turned on, do not attempt to work on the wiring for an electric hot water heater. Check to see that the breaker has been turned off and is taped or secured in the off position. The current flowing through a hot water tank might be fatal. Even if you replace the wrong thermostat, you may still be without hot water or have insufficient hot water.
Electric Water Heater Thermostats – Safety Issues
Be sure to turn off the water heater’s electricity before you begin testing or working on the thermostat or the water heater in general; otherwise, you may cause damage to the water heater. The electrical power used to heat the water has the potential to inflict significant harm or death. If you need more information, see the articles “How to Shut Down an Electric Water Heater” and “Electrical Safety Tips” for further information on the necessary procedures to follow when working on an electric water heater.
Check to see that the power is turned off!
Troubleshooting Electric Water Heater Thermostats
It is not safe to work on an electric water heater unless you follow specific safety procedures first. Remove the heater’s power supply first, before proceeding with any further actions. See the article ‘How to Shut Down an Electric Water Heater’ for further information, and be sure to read the part on ‘How to Safely Shut Off the Power’. The hot water tank thermostats are directly linked to the water heater thermostats. It is likely that the tank will be quite hot. Please refer to the section entitled “Cooling Down a Hot Water Tank” in the article entitled “Stopping an Electric Water Heater” for information on how to reduce the temperature of the water in the tank.
How do I adjust the water temperature?
The thermostats for electric water heaters have a dial on them that you may turn to change the temperature of the water. This issue is covered in greater depth in the article titled “How To Adjust a Water Heater Thermostat. “. It is not necessary to boost the water temperature in order to create additional hot water. The factory settings will be adjusted to a safe degree of protection. Raising the temperature can result in burns and scalds, and it should only be done with utmost caution to avoid injury.
It’s possible that the thermostats themselves are the source of the problem.
It is also possible that the heating element has failed; see’Electric Water Heater Element Testing’for instructions on how to check the elements. Not sure what the source of your problem is? See the page under ‘How To Troubleshoot Electric Water Heaters’ for more information.
How do I test a thermostat to see if it is working correctly?
A dial is located on the thermostat of an electric water heater, and it is used to regulate the temperature of the water being heated. This issue is covered in length in the article titled “How to Adjust a Water Heater Thermostat.” It is not necessary to raise the water temperature in order to create additional heat. At a safe level, the factory settings will be used. Elevating the temperature can result in burns and scalds, thus it should only be attempted with extreme caution. There is no difficulty with the temperature setting if you have insufficient hot water.
To learn more about testing electric water heater thermostats, see’How To Test Electric Water Heater Thermostats’on our website.
Having trouble figuring out what the issue is is?
How do I replace an electric water heater thermostat?
It is necessary to remove the old thermostat before installing the new one. The article’Installing a Water Heater Thermostat’will give you with step-by-step directions on how to remove the old thermostat and replace it with the new.
Where can I purchase a new water heater thermostat? How much do they cost?
Another obstacle you will have to overcome is the purchase of a new thermostat. The section on ‘Purchasing a Water Heater Thermostat’ in the article ‘Installing a Water Heater Thermostat’ will provide you with some advice on how to go about obtaining one of these thermostats.
How do I find out if my water heater elements are bad?
The heating components are another component that is closely related. If the thermostats are in proper working order and you still do not have hot water, it is possible that one or both of the components are faulty. For more information and procedures to follow, please see the page titled “Electric Water Heater Element Testing. ”
Summary
When it comes to electric water heater thermostats, there are primarily two reasons to be concerned about them. The simplest and most straightforward step is to alter the temperature. Unless you are dealing with some uncommon situations, you will not need to do this very often. In addition to this, one or both of the thermostats may be faulty, which is a more common problem. With any luck, this information will have directed you in the correct path for a solution.
Water Heater Thermostats
This video shows you how to quickly and easily change the thermostat on an electric water heater. Learn how a water heater thermostat works, what varieties there are, what issues they might cause, and how to test and fix one for yourself. Get Quotes from Highly Qualified Water Heater Professionals! Get Free Estimates on Your Project!
In this article:
In a nutshell, hot water heater thermostats are adjustable thermostats that are used to regulate the temperature of the hot water that is released from the heater. They are surface mounted, with the element fitted in a bracket that holds it against the tank’s side.
Because the rear side of the thermostat is in direct touch with the tank’s surface temperature, it responds to changes in the tank’s surface temperature. It is possible to reach the thermostats behind the access panels on tank-type heaters.
What is the purpose of a thermostat?
Thermostat Every electric water heater is equipped with at least one heating element for water heating, one thermostat for temperature control, and one high limit switch to safeguard the device from overheating conditions. It is necessary to use different hot water temperatures for different purposes. Showering, dishwashing, and clothes washing all require hot water, which is why a hot water heater thermostat is used to regulate the temperature of the water. In order to control the electrical current that is transferred to another thermostat or a heating element when a request for a temperature change is received, the thermostat must be set to the desired temperature.
- The top thermostat is the primary thermostat, and it is equipped with a high-limit switch.
- The upper thermostats and the lower thermostats are not the same.
- The high limit switch is positioned in the same region as the top thermostat, and it is equipped with a manually reset (ECO) button that trips when the water temperature reaches an unusually high level (over 120°F) (above 170 F).
- Setting the thermostat on a hot water heater to roughly the same temperature as the bottom element, or setting the top element to a little lower temperature than the bottom element, is recommended so that the bottom element activates first and heats the water from the bottom up.
- They are also equipped with a high limit switch.
How does it work
If the water in the heater’s tank is too cold, the upper thermostat activates and provides 240 V of electricity to the upper heating element, which heats the water to the desired temperature. For as long as there is a need for heat or until the higher thermostat is fulfilled, the electric element warms the water on demand. The water in the tank is now heated, but just in the upper portion of it. If there is a significant demand for hot water, this is advantageous. What, on the other hand, is going on at the bottom section of the tank, where the water is still cold?
The heating process begins as soon as the bottom heating element reaches 240 volts. This means that as soon as the bottom thermostat is satisfied and the desired temperature is attained, the power is cut, thereby terminating the operation. All of the water in the tank is now boiling.
How to set the temperature on a thermostat
If the water in the heater’s tank is too cold, the upper thermostat activates and provides 240 V of electricity to the upper heating element, which heats the water to a comfortable temperature. As long as there is a need or until the higher thermostat has been fulfilled, the electric element will heat the water. Even yet, just the water in the upper portion of the tank is now heated. In situations when there is a significant demand for hot water, this is advantageous. How about the bottom of the tank, where the water is still ice cold?
The electricity is diverted to the lower thermostat as soon as the top thermostat’s requirements are met.
This means that as soon as the bottom thermostat is satisfied and the desired temperature is attained, the power is cut, thereby terminating the operation.
- The electricity to the water heater should be turned off completely at the main switch of the fuse box or the main circuit breaker. Removing the access panel and its cover, as well as folding the insulation away from the controls, makes it easier to reach the controls. Rotate the adjustment knob to the appropriate setting (temperature) by using the screwdriver to do this. Reinstall the cover, access panel, and insulation, then switch on the electrical supply and the water heater to complete the installation.
Troubleshooting thermostat problems
- If the top thermostat is faulty, it should be checked and replaced. To manually reset an ECO button in the event that the high limit switch has been tripped: If the thermostat is grounded, it should be checked and replaced. The thermostat is out of calibration
- If feasible, calibrate it
- If this is not possible, replace it.
Not enough hot water
- If the top thermostat is not working properly, it should be replaced immediately. To manually reset an ECO button in the event that the high limit switch has been tripped. If the thermostat is grounded, check it and replace it. The thermostat is out of calibration
- If feasible, calibrate it
- If this is not possible, substitute a new thermostat.
Slow hot water recovery
The lower thermostat is faulty, and it should be replaced.
Water is too hot
- It is necessary to replace the lower thermostat.
Protection against high hot water temperatures
There are just a few things you can do to keep yourself and others safe from unintentional burns. Installing a temperature limiting valve that attaches to taps to limit hot water flow, or installing a mixing valve to lower the temperature of hot water by mixing cold and hot water, are two options for reducing hot water temperature.
How to test a thermostat
Because some tests are not accurate when the heating element is open or grounded, testing heating elements and thermostats are normally done in conjunction with one another. A screwdriver and a multimeter are required for this test, as are other equipment. The instructions in the following section are for testing an electric water heater made by the Rheem/Ruud company, but they may be applied to other manufacturers as well.
- Using the thermostat terminals, verify that the water heater is receiving electricity. 240 V should be displayed on the meter, indicating that there is electricity (terminal 1 and 3). If there is no power, the power source should be checked. Check that the high limit switch (terminals 2 and 4) is receiving power. After that, decrease the temperature on the lower thermostat to the lowest setting so that it does not activate, and raise the temperature on the higher thermostat so that it does activate (but only if the water is cold or temperature is below the set one). The purpose of this technique is to inspect the upper thermostat. By connecting the meter prongs to terminal 1 of the upper thermostat and the blue wire of the heating element, you can see if there is power between the thermostat and the heating element. If the meter reads 240 V, it indicates that there is electricity flowing between them. Carry out the method again, but this time terminal 1 will utilize terminal 2. If there is no power, the thermostat is faulty and should be changed immediately
The lower thermostat should be checked next.
- Set the temperature dial on the upper thermostat to the lowest setting and the temperature dial on the lower thermostat to the highest setting so that it calls for heat
- Connect one probe to terminal 1 and the red wire of the bottom heating element to complete the circuit. As long as the reading is more than 240 V, electricity is being delivered. Now connect the probes to terminal 2 and the red wire of the bottom heating element to complete the circuit. It is necessary to change the thermostat if the electricity is not supplied.
Was it ever brought to your attention that severe issues can be averted if routine maintenance and servicing are conducted on schedule and by a qualified plumber? Make contact with a professional!
How to replace a thermostat on the electric water heater (video included)
Note: Attempting to repair a thermostat on a water heater is not suggested; it is preferable to replace the thermostat. Replace it with a new one that is of the same type and has the same specifications. This tutorial applies to both upper and lower thermostats and is divided into two sections:
- The electric power to the water heater should be turned off. Removing the front panel door and folding up the insulating pad are the first steps. Remove the plastic cover that has been placed over the thermostat
- Check to see whether the power is still off using the multimeter one more time. Remove the thermostat from its mounting bracket. Disconnect the cables that are connected to the thermostat. Wires should be labeled to ensure appropriate reconnection to the new element. Remove the thermostat from the water heater
- The replacement thermostat should be screwed into the bracket. The thermostat should be connected via cables. Make sure that you return the thermostat to its original setting. To ensure that everything is working properly, run the heater through a cycle test. Bring back the components that were deleted
- The electricity to the water heater should be restored
- Start the unit and see how it works.
It is also advised that the heating components be checked, cleaned, or replaced if necessary. When reinstalling the thermostat, make certain that it is securely fastened to the tank’s surface using screws or bolts (flush). A wiring schematic may be found behind the access cover; refer to it to ensure that the wires are properly reconnected to the thermostat. The lower heating elements and thermostats of your electric water heater will be used more frequently, will be subjected to greater lime build-up, and will fail more frequently than the top ones if your water heater has two heating elements and two thermostats.
Some technical information can be found on the back of the element or on the main energy guidance label, depending on the model. Get Quotes from Highly Qualified Water Heater Professionals! Get Free Estimates on Your Project!
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How to Test, Troubleshoot & Repair an Electric Water Heater Thermostat: DIY Guide
How to replace the drain valve; Testing and replacing heating components – a buyer’s guide Setup, issues, testing, and replacement of thermostats are covered. Replace an anode rod in the following manner: Replace a thermocouple in the following ways: Changing a TPR valve; repairing a TPR valve How does a dip tube operate, and how do you change the tips? Heat traps; Gas valves; Mixing valves;
What Is The Purpose of an Electric Water Heater Thermostat?
We wash our clothes, do the dishes, and take a nice shower every day. However, the amount of hot water we consume for these tasks is not the same. Furthermore, the thermostat is essential since it regulates the temperature of the electric heater. An electric water heater is, at its most basic level, a piece of electrical equipment that consists of three components: a heating element, a thermostat, and a switch. Electric water heaters are used to heat water for various purposes. As a result, the thermostat functions as a switch that is actuated when the temperature of the water changes.
- When it senses a drop in water temperature, it will activate the elements, causing them to generate heat.
- So, how does it determine if the water is cold or hot to drink?
- Furthermore, there is no insulator at the point where the tank meets the thermostat.
- Having stated that, when electricity is introduced into the device, the heating element becomes extremely hot and begins to convert the power into heat.
- Finally, the high limit switch keeps the hot water from becoming scorching hot while it is running.
How Does An Electric Water Heater Thermostat Work?
Electric water heaters are classified into two categories:
- In addition to the single element water heater, there is also a twin element water heater.
The single element type is comprised of a single element thermostat as well as a single element heating element. Tanks are often lower in size since only a single thermostat is required to regulate the temperature. Two thermostats and two heating elements are found in the dual element water heater, on the other hand. The majority of water heaters are dual-element water heaters, which is what we’ll be focusing on throughout the remainder of this article. A single element heater, on the other hand, may be checked and changed in the same manner.
- The thermostats for electric water heaters generate heat in the tank by enabling energy to flow into the elements of the water heater.
- The top thermostat, which is also the principal thermostat, regulates the heating element in the top part of the unit, as well as having a high limit switch.
- Keep in mind that the high limit switch, which is placed in the same region as the higher thermostat, includes a reset button that activates when the water temperature becomes too warm (over 170F).
- A 240-volt power supply is used to heat the water, which is subsequently heated by the higher heating element.
- The problem is that only the water in the upper part of the tub becomes heated, while the water in the lower half is either chilly or lukewarm at best.
As the bottom heating element gets 240 V, it warms the water in the bottom region to the temperature that has been specified before the process is completed and turned off. The water in the tank is now completely heated throughout.
Problems with Electric Water Heaters
Sometimes, when your heating elements or water heater thermostats fail, you will notice a difference in the performance of your device. If the upper element or thermostat in your water heater breaks, the water heater may be unable to provide hot water. And whether it’s the bottom element or the thermostat that’s defective, you’ll find that you’re running out of hot water quite soon as well. These, on the other hand, might be a result of the cold weather or pipes that are not properly insulated.
However, it is possible that this is due to the thermostat being set too high or the changing of the seasons.
Other issues might arise as a result of improper tank maintenance or excessive water pressure at home.
How to Test an Electric Hot Water Heater Thermostat and Fix it: Step by Step Guide
We’re going to test both the thermostats and the heating components in our unit to be certain that we’re not dealing with a false alarm. It’s important to note that if your elements are open and grounded, the algorithm may produce a misleading result, which is why we’re also evaluating them. It is necessary to have a Flathead and Philips screwdriver, as well as a digital multimeter, in order to carry out the test described in this section. Let’s get this party started.
Step 1: Turn the power source off
Locate the water heater breaker panel on your circuit breaker panel and switch off the water heater or the hot water supply.
Step 2: Remove the outer access panels
With a flathead screwdriver or 1/4-inch nut driver, pry up the top and lower thermostat access panels on the unit’s left and right sides.
Step 3: Remove the insulation
You have two options for removing the insulation: either entirely remove it or fold it over the thermostat. As well as removing the plastic safety barrier that was covering the thermostat and heating element, Also, use tape to hold the insulator in place as you work on this step, and be careful not to yank the wiring out as you work.
Step 4: Check the high limit switch button
Check to see whether the red high limit reset button has been triggered by accident. If it has, you should push it. The red switch button may trip on occasion if the heating components fail, if the connections on the thermostat have fused closed, or if the thermostat is not calibrated properly.
Step 5: Disconnect the wires
Using your Philips screwdriver, disconnect the wires that are entering each terminal on your computer.
Step 6: Turn the temperature setting to the highest
Make sure that the temperature on the top thermostat is set to its maximum level, and that the scale on your multimeter is set to RX1.
Step 7: Check the thermostat and heating element with a multimeter
Set the resistance of your analog or digital meter to the lowest possible value, which should be 200 ohms. You should hear a click sound at this point. Then attach the black probe to the screw terminal on the left side of the screw terminal. In addition, connect the second red probe to the other terminal, which is still on the left side of the board.
Then, using your reading, check to see if the thermostat is still operational. As long as the meter shows zero or a reading that is very near to zero, your thermostat is in proper operating order. However, if the reading is very broad, you may have a faulty thermostat. Credits:
Step 8: Repeat the process for the right side
Place an ohm meter or an analog meter at the lowest possible resistance, which should be 200 ohms. An audible click sound should be heard. Afterwards, connect the black probe to the screw terminal on the left side. Add another red probe to another terminal that’s still on the left-hand side of the workstation. Then, using your reading, check to see if the thermostat is still operational. In this case, your thermostat is operating properly if the meter displays a reading of zero or a value extremely near to it.
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Step 9: Take the meter reading on the lower thermostat
Set the resistance of your analog or digital meter to its lowest setting, which should be 200 ohms or less. You should be able to hear a clicking sound. After that, connect the black probe to the screw terminal on the left side of the screw terminal. Also, connect the second red probe to the other terminal, which is still on the left side of the circuit. Then, using your reading, check to see if the thermostat is still working. In this case, your thermostat is operating properly if the meter displays a reading of zero or a value extremely near to zero.
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How to Replace A Faulty Thermostat on an Electric Water Heater
It is rather simple to replace a malfunctioning thermostat. Furthermore, purchasing a new one is inexpensive. As a result, even if the problem is with a single thermostat, we’re going to replace both of the thermostats. Prior to doing so, you’ll need to make sure that all of your thermostats are from the same brand. If you are unable to obtain this product, another one from a reputable brand would suffice. You’ll need a few tools.
- A flathead screwdriver, a Philips screwdriver, a digital multimeter or a voltmeter, and a replacement thermostat are all necessary tools.
Now it’s time to get started.
Step 1: Turn off the power supply to the heater
We’ll get right to it.
Step 2: Remove the outer access panel and insulation
Electric water heaters feature access panels on the outside that protect the thermostat and heating components. Remove the insulating pad and plastic covering by unscrewing the nut, taking care not to contact the wires in the process.
Step 3: Take out the Thermostat
Take a photo of the wiring before you remove the malfunctioning old thermostat so that you can remember which wire goes into which terminal while you’re attaching the new thermostat. Alternatively, you can label the wire. Using your multimeter, you should also check to see if it is turned off. Then, using a Philips screwdriver, remove the screw terminals and separate the wire from the terminals. After that, you may peel the thermostat away from its attachment clamps and bracket. However, proceed with caution so as not to harm the clips.
Step 4: Install the new thermostat
After you’ve successfully removed the broken thermostat from the water heater, you’ll need to fix the new thermostat installed in the water heater. Position it appropriately so that it rests comfortably on the surface of the storage tank, and attach the appropriate clips by referring to the image you captured in the preceding step. In addition, connect the circuit wires to their corresponding screw terminals and tighten the screws on the terminals.
In addition, it may be a good idea to examine the heating components, clean them, and replace them. You should conduct thorough study before making any purchases, such as acquiring a new water heater.
Step 5: Set the temperature of your new thermostat
Following the successful removal of the malfunctioning thermostat, you will need to fix the new thermostat installed in the water heater to ensure that it functions properly. Adjust its position to ensure that it rests comfortably on the surface of the storage tank, and attach the appropriate clips by referring to the image you captured in the preceding step. In addition, connect the circuit wires to their corresponding screw terminals and tighten the screws to secure the connections. In addition, it would be a good idea to examine and clean the heating components, as well as replace them.
Step 6: Replace every other thing you took out
Having completed your setup, it is now time to reinstall your insulators as well as the chamber access panel. After that, reconnect the power supply by turning on the water heater breaker on the circuit breaker panel to the water heater.
Step 7: Cycle test your electric water heater
If you want to test if your water heater heated your water sufficiently, you may turn on the hot water faucet for two hours and observe if the heater did a good job. Troubleshooting Other Water Heater Issues and How to Resolve Them Leaks of water: The majority of the time, faulty valves and plumbing connections are to blame for water leaks in the home. However, corrosion in the water heater tank or loose components in the water heater tank might be the source of the problem. If your tank has rusted beyond repair, you will have no choice except to replace it.
- Noises coming from the tank: If your tank is making noises such as rumbling, popping, or high-pitched sounds, it might be due to boiling water.
- Things’s a simple matter of putting it back together.
- If it does not function, the tank should be replaced.
- It’s also possible that the corrosion is occurring in your pipes.
- If the water flowing through your home smells like rotten eggs, it’s possible that bacteria has accumulated in your hot water tank over time.
- You, on the other hand, cannot achieve this on your own.
Wrapping up
You should now be aware of the measures to take in order to simply test and replace your faulty water heater thermostat. Working with electricity, on the other hand, may be quite dangerous, therefore take steps to ensure that the power supply to your water heater is always turned off. Another thing to keep in mind is that silt that accumulates at the bottom of water heater tanks is the most significant factor in lowering the performance of water heaters over time. It might also lead to the overheating of your heater.
Make it a point of duty to flush the sediment from your heater on a regular basis to ensure it lasts as long as possible without needing to be repaired or replaced. Other options include installing a sediment filter and/or a water softener in your water supply.
How to Test a Water Heater Thermostat and Replace it if Needed
Check the thermostat if your hot water isn’t getting hot enough, according to the instructions. Do you, on the other hand, know how to test a water heater thermostat? And, if it turns out to be problematic, do you know how to repair the thermostat on your water heating system? All excellent questions, all of which will be addressed in this essay! There are two possible explanations for why your electric water heater isn’t heating the water. Perhaps the heating element or the thermostat is not functioning properly.
It’s actually not as difficult as it appears!
Water Heater Thermostat Basics
The electric water heater thermostat is positioned on the front of the water heater tank, beneath an access panel that provides access to the tank. The thermostat is in charge of maintaining the temperature of the water in the tank. It does this by opening and closing connections in order to switch on and off the flow of electricity to the heating elements, which are immersed in the tank and are responsible for heating the water in the tank. There is a bi-metal switch that is flush with the wall of the water heater’s tank and operates the water heater.
The bi-metal switch on your water heater will open when the temperature of the thermostat reaches 120°F, preventing electricity from flowing to the heating element.
When the temperature falls below the 120°F set point, the polar opposite occurs.
This video will demonstrate how the thermostat on your water heater operates.
Identifying Which Thermostat is Faulty
With a capacity of 30 gallons or more, the vast majority of water heaters employ two heating elements, each with its own thermostat. It is hooked into the thermostats so that only one heating element is activated at a time. The upper thermostat is responsible for bringing the top third of the water in the tank to the desired temperature. After that, it shuts off and switches the electricity to the lowest thermostat setting. The two thermostats are not identical, and if one fails, the water heater will react in a different way than if the other fails.
How to Identify Which Thermostat Failed
- With a capacity of 30 gallons or above, the vast majority of water heaters employ two heating elements, each with its own thermostat. It is designed such that only one heating element is activated at a time by the thermostats. It is achieved by adjusting the higher thermostat to bring approximately one-third of the tank’s water to the desired temperature. After that, it shuts down and switches the electricity to the lowest thermostat position. The two thermostats are not identical, and if one fails, the water heater will react in a different way than if the other does fail.
How to Test a Water Heater Thermostat
First and foremost, you must ensure that there is no discontinuity. You’ll need a Phillips and a flat head screwdriver, as well as a multimeter, to complete this task. Always switch off the electricity to your electric water heater before starting any work on it. Then double-check that the power has been turned off. Here’s how it’s done:
Shut Off the Power to Your Water Heater
- At the main electrical panel, turn the breaker to the OFF position. Remove the thermostat’s access cover and set it aside. Removing the insulation and plastic protective cover is the first step. Touch one of the multimeter’s probes to a grounded metal object (such as the tank casing, which is unpainted metal)
- Connect the second probe to each thermostat terminal as well as the terminals of both heating elements. At all times, the multimeter should display zero voltage (Zero). To visually see how to switch off the electricity to your water heater, watch the video below.
How to Test a Water Heater Thermostat for Continuity
It’s time to check the thermostat on your water heater now that the electricity has been turned off at the main electrical panel.
First and foremost, you must understand what you are doing.
- The thermostat on your water heater should be tested when the electricity is switched off at the main electrical panel. First and foremost, we must understand what we are doing.
- It’s time to check the thermostat on your water heater now that the electricity has been shut off at the main electrical panel. First and first, it is necessary to understand
Step number three.
- Test the lower area of the thermostat by connecting one lead to the common terminal (located next to the temperature setting) and the other lead to the left heating element terminal
- This will reveal whether the thermostat is functioning properly. If the temperature of the water in the tank is lower than the thermostat’s set temperature, the resistance reading on the multimeter should be near to 0 ohms. Move the lower lead from the left heating element terminal to the right heating element terminal by pulling it up and out. The continuity indicator on the multimeter should indicate “NO continuity.” If the temperature of the water in the tank is higher than the thermostat’s set setting, you should observe the polar opposite of what you want. If the upper thermostat is functioning properly, you’ll need to check the lower thermostat as well.
- When you are finished, you may test the lower section of your thermostat by connecting one of its leads to the common terminal (which is located next to the temperature setting) and another lead to the left heating element terminal. It should read near to zero ohms of resistance if there is no heat present in the water in the tank
- Otherwise, it should read close to one hundred ohms of resistance. Move the lower lead from the left heating element terminal to the right heating element terminal by pulling it up and down. The continuity reading on the multimeter should be zero. It is expected that you will experience exactly the opposite consequences if the water in the tank is warmer than the thermostat’s set temperature
- In order to determine whether the upper thermostat is functioning properly, you must first test the lower thermostat
Watch the Video
Generally speaking, if you’ve decided that one of your water heater’s thermostats is malfunctioning and must be changed, it’s preferable to repair them both at the same time. Thermostats are available for purchase singly or as part of a set.
Buying a Tune-up Kit
Perhaps you might consider getting a tune-up package, which will contain both the upper and lower thermostats, as well as two new heating elements for your furnace. It may cost a few dollars extra, but you’ll notice a significant improvement in the way your water heater functions in most circumstances. This is especially beneficial if your water heater has at least a few more years of useful life left in it. Tune-up Kit for Any Vehicle The ZERO EWH-01 Tune-up Kit is designed to work with the majority of electric water heaters.
An OEMtune-up kit for electric water heaters is also available from Rheem.
Make sure the heating elements are the suitable size and type for your water heater.
Buying Upper or Lower Thermostats
Although it is usually a good idea to repair both thermostats at the same time, there are situations when it is just more convenient to replace only the malfunctioning one. This is especially true if you have plans to acquire a new water heater in the near future and are only attempting to get your present water heater up and running until you can make the purchase. Camco Thermostat, Upper Thermostat This upper thermostat from Camco offers a built-in reset button, changeable temperature settings, and a one-year guarantee on the mechanical components.
If you want a lower thermostat, theCamco 8123is a decent, low-cost choice, and of course,Rheem also sells one in this configuration.
Single Element Water Heaters
Although we’ve concentrated on double-element water heaters, certain models, particularly those with tanks of 20 gallons or less, may heat water with a single heating element. These water heaters are connected in a different way and require a single element thermostat to function properly. They may appear to be very similar to an upper dual element thermostat, however they have fewer wire terminals than an upper dual element thermostat. Camco Thermostat with a Single Element The Camco 07843 Single Element Thermostat is equipped with a built-in safety switch, changeable temperature settings, and a protective cover for further protection.
How to Replace a Water Heater Thermostat
Water heater thermostat replacement is a simple process that you should be able to complete on your own without any difficulties. Although many homeowners are comfortable doing the work themselves, many choose to employ the services of a professional plumber.
You’ll need a Phillips and a flathead screwdriver, as well as a multimeter and your new thermostat to complete this project. Make certain that the thermostat you select is compatible with your water heater.
Shut Off the Power to Your Water Heater
- At the main electrical panel, turn the breaker to the OFF position. Remove the thermostat’s access cover and set it aside. Removing the insulation and plastic protective cover is the first step. Touch one of the multimeter’s probes to a grounded metal object (such as the tank casing, which is unpainted metal)
- Connect the second probe to each thermostat terminal as well as the terminals of both heating elements. At all times, the multimeter should display zero voltage (Zero).
- Disconnect the cables from the thermostat. Pay attention to how they’ll be reconnected
- This is important. To remove the thermostat from the retaining bracket, carefully lift it out.
- The old thermostat should be replaced with a new one. Check to see that it is the proper thermostat for your heater. Check to see that the rear of the thermostat is snugly pressed against the tank’s inside. The cables to the thermostat should be reconnected. Replace the protective cover with a new one.
Step number three.
- Check and make necessary adjustments to the temperature setting to 120°F. Remove the insulation and access cover and replace them. Activate the water heater’s power supply
Watch the Video
Some frequently asked questions about water heater thermostats have been included below for your convenience:
Are Electric Water Heater Thermostats Universal?
No. Some water heaters employ two heating elements, while others only use a single heating element to heat the water. These are not the same, so you’ll want to make sure you get the right one for your water heater before buying it. Aside from that, in dual-element water heaters, the lower and top thermostats are not the same and cannot be used in combination. Because the top thermostat is bigger and contains more terminals than the lower thermostat, it is preferred. As a recommended practice, always check the information tag on your water heater to ensure that you are purchasing the suitable thermostat for your system.
How to Reset a Water Heater Thermostat?
If your thermostat has tripped, you can remove the insulation from the tank by opening the access cover on the front of the tank. On the thermostat, there should be a red button to press. To reset the device, simply press it in. If it trips again, you may be dealing with a more significant issue (see below).
What Causes a Thermostat to Trip?
There are a variety of reasons why a thermostat may malfunction. A defective thermostat or heating element are the most typical causes, but it can also be caused by a poor electrical connection or even a malfunctioning reset button. If you are having trouble determining the source of the problem, you should consult with a professional plumber.