7 Steps to Test Water Heater Thermostat
It is possible that you may detect two thermostats on your electric water heater when you inspect it: one at the top and one at the bottom. Each of these devices regulates the temperature of two separate heating components. If you switch on the hot water faucet and only cold water comes out, this indicates that the higher thermostat has failed. However, if the water is hot at first and subsequently gets chilly, this indicates that the lower thermostat has been destroyed. You will, however, need to understand how to test a water heaterthermostat in order to identify the defective device.
Regardless of whether you have a propane tankless water heater or any other type, the thermostat is an excellent tool for controlling the temperature.
How Does A Thermostat Work?
In most cases, an electric water heater has three primary characteristics. It is equipped with an electric heat source as well as a temperature control system and a switch to protect the device from excessive heat. A thermostat may be used to create hot water that can be used for a variety of applications. Consider that the degree of heat necessary for washing may differ from the level of heat required for bathing, for example: Furthermore, it regulates the amount of electricity that flows to another thermostat or heating element, among other things.
- The primary thermostat is located on the top of the unit, which also has a high limit switch.
- Both thermostats (which are installed on the same water heater) do not have the same set of capabilities.
- On the same wall as the top thermostat, you will find the high limit switch.
- This button can be used to reset the system to its default settings.
- Alternatively, you may set the upper element to a lower temperature, letting the bottom element to operate first, so saving energy.
- They do, however, have a high limit switch, similar to the bigger water heaters.
How to Test Water Heater Thermostat
The three most important characteristics of an electric water heater are: It is equipped with an electric heat source as well as a temperature control system and a switch to keep the device from being overheated. To provide warm water for a variety of applications, thermostats are commonly used. Consider that the degree of heat necessary for washing may differ from the level of heat required for bathing. Aside from that, it regulates the flow of electricity to another thermostat or heating element.
- It is the primary thermostat, with a high limit switch, that is located on top of the unit.
- It is not the same characteristics on both thermostats (which are installed on the same water heater).
- The high limit switch is located on the same circuit as the higher thermostat.
- Clicking on this button will return it to its default configuration.
- Alternately, you can reduce the temperature of the upper element, enabling the bottom element to activate first, as shown in the diagram below: Smaller tanks (up to 30 gallons) are controlled by a single thermostat and heating element, which simplifies the process of temperature regulation.
In contrast to the bigger water heaters, they employ a high limit switch.
- Make your way over to the thermostat terminals and check to see whether it is receiving electricity. It is possible that terminals 1 and 3 will show a reading of 240V if this is the case. However, if there is no reading, the power source should be checked. Examine the high limit switch for any signs of current as well. By turning the thermostat’s dial to the lowest position, you can disable the lower thermostat. After that, raise the temperature of the top thermostat to check for malfunctions. Connect the prongs of the multimeter to the terminal 1 and the blue wire of the heating element to test the voltage. This will assist you in determining whether or not electricity is being delivered between the upper heating element and the blue wire
- If the instrument reads 240V, it indicates that power is being supplied to the setup. After that, connect the prongs of the heating element to terminal 2 and the blue wire of the heating element. However, if there are no readings, this indicates that the thermostat is malfunctioning. Reduce the temperature of the heater to a lower setting. Adjust the dial on the top thermostat to the smallest setting possible while setting the dial on the other thermostat to the highest setting possible
- Return to the bottom heating element’s terminal 1 and the red wire that connects to it. Power should be detected by placing a probe on each of them. If the voltage reading is 240V, there is power in the setup
- Connect the probes to terminal 2 and the red wire of the bottom heating element
- And test the system. If you are not getting any readings from your thermostat, you will need to replace it.
How to Replace a Faulty Thermostat on an Electric Water Heater
Installing an electric switch to change the thermostat on an electric water heater is as simple as turning on the water heater. Knowing how to test a thermostat allows you to do the necessary repairs without having to empty the storage tank first. In order to avoid any potential mishaps, you must first cut off the power source and check the cables for voltage before proceeding with the work. You will need to adjust both thermostats on your water heater if you want really hot water. If the problem is caused by a single thermostat, it is advised that you replace the two thermostats because they are quite inexpensive to replace all at once.
If you are unable to locate a suitable replacement from the same manufacturer, try for a similar item from another manufacturer.
Deactivate the Power Supply
Switching off the circuit breaker that is attached to the water heater will turn off the electricity to the water heater. Water heater breakers are typically comprised of two distinct single-pole switches with a combined 30 amp rating. Some versions, on the other hand, have more amps. The panel that covers the thermostat and heating element of your electric water heater should be removed. It is possible that you may need to use a screwdriver on some versions since the panels are bolted together.
To avoid electrical shocks, make sure there is no current flowing through the thermostat.
Pull out the Faulty Thermostat
Take a photo of the thermostat’s connections. After you have learnt how to test a thermostat, you may use the illustration as a reference. If you are feeling creative, you may also produce a short sketch. Remove the thermostat’s screw terminals by unscrewing both of them. Then pull each wire on both of them out one at a time. After that, unclip the thermostat from its connection clips and carefully lift it out of the thermostat chamber. To avoid damaging the clips, apply only the bare minimum of force.
Set Up the New Thermostat
Insert the new thermostat into the matching clips on the wall. Check to see that it is properly resting on the surface of the storage tank. Connect the circuit wires to the matching screw terminals on both sides of the board. Tighten the screws to secure them in place. Increase or decrease the temperature setting on your thermostat according to your preferences. A flat blade screwdriver will be required in this situation. It is recommended that you set the temperature to 120 degrees Fahrenheit.
Add Final Touches
Insert the new thermostat into the appropriate clips on the existing thermostat. Inspect the tank’s surface to ensure that it is properly supported. Using the proper screw terminals, connect both circuit wires to the circuit.
Tightening the screws will secure them. Set the thermostat to the temperature you desire by turning the dial. Flat blade screwdrivers are required for this task. You should set the temperature to 120 degrees Fahrenheit, according to the recommendations.
How to Troubleshoot a Defective Thermostat on An Electric Water Heater
Troubleshooting the thermostat on your water heater may appear to be a complicated task. This tutorial will assist you in doing this task without the need to consult an expert.
- To turn off the electricity to the thermostat, go to the circuit breaker and turn it off. Because it protects you from electrical shocks, this procedure is really necessary. A two-pole breaker will cause both breakers to trip at the same time if you are working with two breakers. Remove the two panels that protect the thermostat from the wall. Insulation that corresponds to the aperture is found beneath the cover. Remove the item and store it aside for later installation. The thermostat and heating element should both have a plastic panel on them. A button may be found beneath the panel. It should be pressed to confirm that it is in great working order. Keep an eye out for a “snapping” motion when you press the button. In the event that you experience any, turn on the power and allow it to run for a few minutes. Check to see whether there is no power to the unit, especially if you want to continue working on the equipment. Make use of a non-contact voltage tester to test a pair of wires towards the top of the circuit. If you don’t see any lights or hear any beeps on the meter, this indicates that there is no energy flowing through the thermostat. Even if you do not see any readings on the tester, continue to work on the machine as if there were power. Remove the plastic cover from the thermostat by gently pulling it out or unscrewing it. Avoid inserting your fingers too far inside the device in order to avoid potential mishaps. Remove the battery and connect it to a voltmeter with a minimum voltage of 240 volts on it. Place the test lead on all of the higher screws. Do not remove the lead. If you get a reading, it means that the power is switched on
- Turn it off and check again later. There must be no electricity running through the device.
An electric water heater, like a tankless water heater, is equipped with a thermostat. Fortunately, just a few equipment are required for testing and repairing a malfunctioning thermostat, including a multimeter and a pair of screwdrivers. To solve this dilemma, you don’t even need to have any special abilities. All you have to do is follow these simple instructions.
- Turn off the electricity
- Check the unit’s functionality. If there are any issues, you should remove the present thermostat and replace it with a new one. In order to avoid any shocks while working, it is recommended that you periodically check the equipment for any current.
We really hope you found this information informative. If you have any remarks, please leave them in the comment section below.
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
- Water heater will cease heating water completely if your higher thermostat (or heating element) is faulty. Because the top thermostat is in charge of the lower thermostat, if the upper thermostat fails, the lower thermostat will never turn on. Theft of the Lower Thermostat- If your lower thermostat (or heating element) fails, you will either notice that the hot water is tepid or that the hot water is quickly depleted. Due to the fact that the higher thermostat will signal the heating element to heat just the top third of the water in the tank, but the lower thermostat is defective and is unable to switch on the bottom heating element, this occurs.
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.
- Check to see if the reset button has been pressed. If it has, go ahead and reset it
- Otherwise, wait. Remove the wires from the thermostat and set them aside. Pay close attention to how they are linked together.
- By pressing the reset button, one of the multimeter leads will be connected to the left side terminal. The other multimeter lead to the other terminal on the left side of the reset button should be touched as well. If the thermostat has continuity, the multimeter should show a reading close to one hundred percent. This indicates that the thermostat is malfunctioning and must be changed
- Otherwise, this indicates that the thermostat is working properly. Rerun the test on the right-side terminals by pressing the reset button one again.
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 close to zero 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.
- Disconnect the power cables from the lower thermostat and turn off the electricity. Using the first lead, connect it to a single terminal and the second lead to the other terminal
- If the water temperature is lower than the thermostat’s set temperature, the resistance shown by the multimeter should be near to 0 ohms. If the water temperature is higher than the thermostat’s programmed temperature setting, the multimeter should show no continuity
- Otherwise, it should. A thermostat with the opposite reading indicates a defective 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
- Water heater thermostat replacement is a simple process that you should be able to complete on your own without difficulty. But for the majority of homeowners, employing a professional plumber is a more comfortable option for them. Along with your new thermostat, you’ll need a Phillips and flathead screwdriver, as well as a multimeter. Inspect your water heater to ensure that you’ve purchased the proper thermostat.
- 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.
- A third step
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.
Test Your Water Heater Thermostat In Minutes: 13 Steps
Because you’ve had a particularly long day, you’ve made the decision to take a shower before retiring to bed. When you turn on the faucet, you’ll be sprayed with ice-cold water. However, where is the hot water? This is nothing new. It will never come! Uh-oh! If this seems like a familiar scenario, you may be the victim of a malfunctioning water heater thermostat, but how can you be certain? We can determine whether or not the thermostat is the source of the problem with a few simple tools and some good old-fashioned elbow work, though.
A flathead screwdriver and a digital multimeter are the equipment you’ll need for this project.
It’s also a good idea to get your hands on the heater’s service manual if you have one.
It is possible that you will get wounded if the essential safeguards are not performed. If you are unsure about anything, proceed with care and/or seek expert assistance. With that being said, let’s get started.
13 Steps to Test a Water Heater Thermostat
- Turn off the electricity. Before you begin, be sure that the power has been turned off. Then double-check your work. Then double-check everything. The fact that it is switched off is highly crucial in order to avoid injury. Locate the water heater circuit breaker on the circuit board by looking at it. Depending on who built the system, it may be labeled as something different, but it should be obvious enough that you would know it was for the heater. However, if you are unsure, you should stop right here and consult with a specialist
- You can get to the thermostats. When you go to your water heater, you will see two panels: one that is higher up on the unit and one that is lower down. One of the panels will be higher up on the unit and the other will be lower down. These include the thermostat and all of its parts
- And Remove the covers from the access points. To remove the top and bottom access covers, use a flathead screwdriver to unscrew them. A flap with a cutout for the thermostat will be located inside
- Flip the flap up to reveal the insulation underneath it. Depending on how it was cut, you may be able to flip it down as well. In any case, check to see that it isn’t interfering with anything.
- Optional: Use masking tape to keep the flap out of the way. If you were successful in obtaining some tape, remove the flap.
- Optional: Tape the flap out of the way to prevent it from falling open while you are working. You should remove that flap with tape if you were successful in obtaining it.
- Optional: Check the voltage with the voltage stick to ensure that the electricity is working properly. Make a double-check to ensure that there is no electricity flowing through the water heater at all times. Placing the stick against any of the terminals and seeing whether or not the stick goes off is recommended. If it does, you’re in trouble
- If it doesn’t, you’re in the clear. If it doesn’t, you’re in the clear. Repeat the procedure for both the top and lower thermostats.
- Prepare your multimeter for use. Inspect the reset button on your multimeter after you have set the dial to the lowest ohms of resistance level. A reset button will be located on the top thermostat. This can be triggered when the water in the tank becomes too hot for a variety of reasons (which we’ll discuss in further detail later). To do this is referred to as “tripping the power.” Reset the reset button by pressing it all the way in if necessary. Disconnect the power cables from the wall outlet. Despite the fact that there is no power flowing through the device, you must separate the connections in order to isolate the thermostat. Take notice of the wires’ alignment in relation to one another. After that, use your screwdriver and undo the terminals and wires until they are no longer connected. Make sure you do this for both the top and bottom thermostats
- Then check the higher thermostat to see whether it is still functional. There will be several mini-steps in this, so please make sure to follow through and do not skip any of them! We’ll have to check to see if the top thermostat is operational.
- Connect the lead of your multimeter to the reset terminal. This should be exactly next to the reset button on the controller. It would also have been the terminal that did not have any power lines running to it
- As a result, Move the second lead to the terminal on the left-hand side of the board. Keep your first lead connected to the reset terminal at all times when doing this. This will be the one that did have the power cable attached to it
- This will be the one that did not. Make a note of the reading from your multimeter. The top thermostat has lost continuity and must be replaced if it displays a reading of 1. The resistance should be zero ohms or very near to zero ohms if the device is in proper functioning condition. Move the second lead to the terminal on the right-hand side of the board. Remember to maintain your first lead connected to the reset terminal at all times when doing this. Additionally, this terminal would have had a power cable connected to it. Make a note of the reading from your multimeter. It should be noted that if it reads 1, there will be no electrical continuity. If it reads zero, you’re in the clear
- If it reads one, you’re in trouble.
- Determination of whether or not the water temperature is lower or greater than the given setting This will also have mini-steps, so let’s get started
- Connect the lead from your multimeter to the left common terminal. This can be located in the lower portion of the thermostat
- However, it is not visible. Make your way to the upper heating element terminal with the second lead. While you’re doing this, be sure that your initial lead is still connected to the common terminal. Make a note of the reading from your multimeter. Alternatively, if your water temperature is lower than it should be, the first reading will be zero ohms (or very near to it), while the second reading will be one (indicating no continuity)
- Relocate the second lead to the terminal of the lower heating element. Check that your first lead is still connected to the common terminal, just as you did in step 12.2. Make a note of the reading from your multimeter. If your water temperature is higher than it should be, the first reading will be 1 (no continuity), and the second reading will be 0 ohms (or very near to it)
- If your water temperature is lower than it should be, the first reading will be 0 ohms (or very close to it)
- Keep track of if the temperature of your water is higher or lower than it should be. If you want to check the lower thermostat, you will need something to compare it against.
- Examine the lower thermostat to see if it is in good working order. This procedure will be similar to step 11, which involved inspecting the top thermostat for structural integrity. For the record, you should have double-checked to see if the power was still on and that the power connections had been unplugged before proceeding.
- Place your leads on the two terminals of your multimeter using your multimeter. 0 ohms should be the measurement if your water temperature is lower than it should be
- Otherwise, it should be 1. (or close to it). If the water temperature is greater than it should be, the measurement should be 1 (no continuity)
- Otherwise, the value should be 2 (continuity).
- So, what’s the ultimate word on the matter? Is it necessary to replace it? If the readings on the upper and lower thermostats are diametrically opposed, then the lower thermostat must be changed. More specifically, if the upper thermostat indicates that water temperature is greater than it should be, but the lower thermostat indicates that water temperature is lower than it should be (or vice versa), your lower thermostat is faulty.
And that’s the end of it! Phew! The process was lengthy, but you have now decided whether or not your water heater’s thermostat is to blame for your problem. But, before you go ahead and put everything back together, you might want to think about lowering the temperature of the water heater a little.
Adjusting Water Heater Thermostats
The temperature is typically set at 140°F (60°C) by default by most manufacturers. Anyone living in a residential situation does not require this level of care! By lowering the temperature to a lower and more realistic figure, you can save energy (and money).
How Do I Adjust the Temperature?
If you haven’t yet closed the thermostat access covers on the heater, you’ve already completed more than half of the job! If this is the case, repeat steps 1 through 6 once again before proceeding. When the covers are removed, you should be able to see a dial with a pointer that is set to the desired temperature. Simply use a flathead screwdriver to change the temperature to the desired setting for your device. We recommend that you keep the temperature between 120°F (49°C) and 140°F (60°C) throughout the event.
Please be sure to turn the breaker back on once you’re finished!
Why Does My Water Heater Keep Shutting Down?
Having changed the temperature and double-checked your thermostats to ensure that they are all in proper operating condition, what is causing the water heater to shut down so frequently? As previously indicated, the reset switch, which is integrated into the thermostats, is responsible for this behavior. Whenever the water temperature within the tank rises to an unsafe level, the reset switch will disconnect the power to the heater and turn off the water heater. Here are a handful of possible explanations on why this may be occurring.
- The heating element is on its last legs. Your heating element’s integrity may be affected as a result of its advancing age. As a result, it will not function as intended. If this is the case, the water in your tank may get overheated, resulting in the reset feature being activated by the tank. The heater will then shut off as a result of the Energy Cut-Off (ECO) Switch being activated. The ECO switch prevents the water from becoming overly hot, and it works in concert with the reset function to provide still another failsafe. Over time, it might become worn out and eventually shatter. Although this alone would not cause the heater to shut down, it is typically a sign of additional issues, such as faulty wiring. If everything else appears to be in working order, it’s possible that the reset switch is tripping due to a short circuit produced by bad wiring. If this wire is exposed to water in any way, whether directly or indirectly, it will represent a significant risk and should be handled by a qualified electrician. Do not attempt to solve or diagnose this problem on your own
- Instead, contact a professional.
And that’s the end of it! The problem with your water heater has hopefully been identified with the help of a few of screws and some poking around with your multimeter. Otherwise, at the very least you’ve altered the temperature so that you may save some energy (money). If you like this post, consider subscribing to our email list so that you can get a head start on all of our future publications. Not ready to make the commitment? It’s not an issue! Everyone is welcome to peruse our other articles, and who knows what they could find?
How to Test an Electric Hot Water Heater Thermostat
There are two thermostats in an electric water heater, both of which are situated beneath access panels on the side of the tank. An electric hot water heater has two thermostats, each of which controls two distinct heating elements — one in the top half of the tank and one in the bottom half of the tank. Typically, when the higher thermostat fails, you will have no hot water at all, but a failed lower thermostat will manifest itself by providing only a limited amount of hot water before the tap water becomes cold.
Tests on the thermostats are carried out using a multimeter, which is a standard electrician’s equipment. Once you’ve discovered which thermostat is malfunctioning, you may replace it and get your hot water heater back up and running.
- A Phillips screwdriver, a flat-head screwdriver, and a multimeter are all necessary tools.
Always turn off the electricity to any electrical equipment before trying any repairs on it.
Turn off the water heater circuit breaker, which is located within the central service panel.
Using a Phillips screwdriver, remove the top and lower access panels from their frames. Electric hot water heater access panels are often located on the side of the unit and have an electrical warning placard affixed to them.
Remove any insulation that may be covering the thermostat or the heating element by pulling it away. Keep an eye out for any wires that may be pulled while changing the insulation.
To adjust the temperature setting on the top thermostat, use a flat-head screwdriver to turn the dial to the maximum setting. A multimeter’s scale should be set to the RX1 setting.
Place one probe on the left screw terminal with the white wire and another probe on the terminal directly above the white wire on the screw terminal on the right side of the board. The reading on the multimeter should be zero. (See illustration) Any other value on the multimeter shows that the thermostat is not working properly.
To do this, use the flat-head screwdriver to lower the top thermostat to its lowest setting. During this procedure, you should hear a clicking sound from the thermostat. One probe should be placed on the terminal above the white wire, and the second probe should be placed on the terminal to which the black wire is connected. In this case, the reading on the multimeter should be zero once more.
Keep the higher thermostat on its lowest setting while you test the lower thermostat on its highest setting. Set the lower thermostat to the highest setting by using a screwdriver to turn it. Make a connection between each terminal on the bottom thermostat with one probe of the multimeter. There are just two connections on the bottom thermostat. The multimeter should show a reading of zero when this occurs.
Reinstall the defective thermostat, and then replace the insulation that was previously placed over the thermostats and heating components. Replace the access panel covers, locking them in place with the retaining screws that were previously installed. The electric water heater will be activated after the circuit breaker has been reset.
Test & Replace a Water Heater Thermostat: DIY Guide
We shall almost certainly all be confronted with the situation of a water heater that is not producing any hot water at some point in our lives. We have two options: either contact a qualified plumber or do it ourselves. Fortunately, most water heaters can be repaired reasonably quickly and inexpensively. There are two primary reasons for a water heater not working: If you’ve never checked or changed a water heater thermostat before, it might seem like a difficult process at first glance. It’s not too difficult.
When bathing or cleaning, no one enjoys using cold water.
If you are experiencing no hot water, we will need to examine the water heater thermostat and, if necessary, replace it. In this post, we will look at how to diagnose your electric water heaterthermostat and how to replace it if it becomes damaged or malfunctioning.
How Electric Water Heater Thermostats Work
When you begin to realize that your water heater isn’t operating as efficiently as it should, the thermostat is more than likely the source of the problem, or at the very least a contributing factor. No need to repair the entire electric heater when you can save yourself both time and money by just replacing the thermostat instead. Once you’ve gone over the following instructions, it will only take a few minutes. Electric water heater thermostats function by opening and shutting connections, which allow electricity to pass to the heating components of the water heater.
- Modern home water heaters are equipped with two heating components as well as two thermostats.
- The higher thermostat differs from the lower thermostat in several ways.
- It is quite rare for both thermostats to fail at the same time (although I do recommend replacing both when one fails).
- Whenever a lower heating element or thermostat fails, the top thermostat and heating element will take over and continue to heat water in the upper part of the hot water storage tank.
Are Electric Water Heater Thermostats Universal?
No, not all water heater thermostats are designed to be interchangeable. It is important to note that there are certain differences in thermostats between single-element and dual-element water heaters. Additionally, with dual-element water heaters, there is a differential between the top and bottom thermostats. In order to properly select a water heater thermostat, you must first determine the number of elements and the voltage of the water heater in question. It is possible to obtain this information from the data tag located on the side of the water heater.
The voltage is inscribed on the end of the heating element, and it may be read with a magnifying glass.
There are more than 50 different household tank-style electric water heaters available on the market, and the thermostats on the majority of them are designed to be interchangeable.
Typical household water heater thermostats are seen in this photo, which includes an upper and lower thermostat for each. Because it is located above the lower thermostat, the thermostat on the left has a high limit switch, which can be identified by the red reset button. The upper thermostat is in charge of controlling both the upper element and the lower thermostat, respectively. When you look at it from this angle, you can see the bottom thermostat, which regulates the lower element. For a replacement kit that includes two heating elements, upper and lower thermostats, and seals, we offer theRheem SP20060 Electric Water Heater Tune-Up Kit, which can be purchased on Amazon.com for about $30.
A universal upperthermostat produced by Rheem is what we’re looking at here. If you merely require a lower thermostat, the Rheem SP11695 Electric Thermostat is a good choice. It is a Rheem lower thermostat that is universal in use.
The thermostat seen here is for a water heater with a single heating element. The thermostat is very similar to an upper dual-element thermostat, with the only variation being the amount of wire terminals on the thermostat. In this case, the single element thermostat has just two terminals on the right side and four on the left side, as you can see in the illustration. If you require a single-element thermostat, the Camco 07843 Single Element Water Heater Thermostat with HLC is a good option to consider purchasing.
The following is a list of the supplies you’ll require:
- In addition, you’ll need a 1/4-inch nut driver or a flathead screwdriver, two Phillips screwdrivers, an analog or digital multimeter/voltmeter, and a new thermostat.
How to Test a Water Heater Thermostat for Continuity – Step-By-Step
We must examine the thermostats for continuity in order to identify whether or not the thermostat has failed. You’ll need an analog or digital multimeter for this, which you can get here. WARNING: Working with electricity is extremely hazardous and can result in death. Before dealing with wiring or electrical connections, be certain that the power is turned off. Follow these procedures to determine which thermostat is malfunctioning.
Step 1: Turn the power off
Make your go to your circuit board and locate the water heater breaker to switch off the power supply. Discover and switch off the breaker that is labeled “water heater” or “hot water” in the electrical panel box where the water heater is located.
Step 2: Remove the outside access covers
To remove the access cover from the upper and lower thermostats, use a 1/4-inch nut driver or flathead screwdriver to pry them off. Fold the insulation back over the thermostat to prevent it from being damaged. To keep the insulation out of the way, use tape to hold it in place. Remove the plastic cover that covers the thermostat on the inside of the house.
Step 3: Confirm power is off to the water heater
Make sure the water heater is not receiving electricity before working on it with a multimeter before doing anything on the thermostat. If you have a voltage stick, you may also use it to measure the voltage. Connect the top and legs of the multimeter at the same time, using the multimeter connectors. The meter should be set to zero. Touch each leg of the water heater while the black connector is in contact with it to ensure there is no electricity.
Step 4: Check the high limit reset button
If the manual reset switch, also known as the high limit reset button, has been tripped, it should be replaced. This button will trip on occasion if any of the following conditions are met:
- There is a short circuit between the thermostat contacts
- The thermostat is out of tune
- The heating element has failed
Step 5: Disconnect the wiring
Take a photo with your phone or a digital camera to use as a reference if it becomes necessary to identify which cables are connected to which terminal in the future. To detach the wiring from the thermostat terminals, unscrew the terminal screws using a Phillips #2 screwdriver and pull the wiring away from the terminals.
Step 6: Check the thermostat with a multimeter
Set the resistance of the multimeter to the lowest ohms possible (typically x10). Using your fingers, squeeze the probes together and adjust the needle to zero to calibrate your meter. To check the resistance of a digital multimeter, set it to the lowest possible value of resistance (usually 200), or, if your multimeter has an option for resistance with tone, choose it. Take one of the black probes from your multimeter and insert it into the screw terminal on the left side of the instrument. Take the red probe and connect it to the other left-side terminal on the other side.
This means that the thermostat is not functioning properly and must be replaced.
For a demonstration, please see the video above.
As soon as you have finished testing your water heater thermostat, you may either reconnect the wire and close the access cover, or you can proceed to the next step, which is replacing the thermostat.
Assuming you have decided that your thermostats do not require replacement, you may proceed to inspect your heating components. How to Test and Replace a Faulty Water Heating Element is a step-by-step guide that explains how to accomplish this in further detail.
How to Replace a Faulty Water Heater Thermostat – Step-By-Step
Once you’ve discovered which thermostat is faulty, it’s time to begin the process of removing and replacing it. Insider’s Tip: As previously said, it is typically a good idea to change both thermostats and heating components on a yearly or biannual basis. The reason for this is that if one of the heating components is beginning to fail, it has the potential to short out the replacement thermostat shortly after it has been placed, causing it to fail. Some of the stages will be repeated in this section.
For those who have not yet tested their thermostats, we will first go through the preparatory processes.
Step 1: Turn the power off
Make your way to the circuit breaker box and look for the switch labeled ‘Water Heater’ or anything along those lines. It should be turned off, making sure to turn off both switches if it is a 220v switch. If you’re not sure which water heater is causing the problem because of outdated stickers or labels, get a professional to turn them off for you.
Step 2: Remove the outside access covers
Remove the cover panel that corresponds to the thermostat that has to be replaced and set the cover panel aside. The coverings for water heater tanks are often located on the side of the tank. Ensure that you do not loose any of the little screws by using the 1/4-inch nut driver or a flathead screwdriver for this section. Remove the insulation from the thermostat as well as the plastic protective cover that covers it.
Step 3: Confirm power is off to the water heater
Each wire should be tested with your multimeter/voltmeter. This may be accomplished by grounding one of the lines and checking each terminal one at a time until the problem is resolved. Even if you have shut off the power at the circuit breaker, you should always double-check your work using one of these meters to ensure that you have not electrocuted yourself. Connect the top and legs of the multimeter at the same time, using the multimeter connectors. The meter should read 0 at this point. Touch each leg of the water heater while the black connector is in contact with it to ensure there is no electricity.
Step 4: Disconnect the wiring
Take a photo with your phone or a digital camera to use as a reference if it becomes necessary to identify which cables are connected to which terminal in the future. Disconnect the wiring from each terminal on the thermostat with a Phillips screwdriver #2. Remove the thermostat from the wall.
Step 5: Remove the defective thermostat
Gently remove the old thermostat by pulling outward on the clips and raising the thermostat up and out of the retaining bracket with your finger or a flathead screwdriver. Caution should be exercised to avoid breaking the retainer bracket. It is possible that breaking this retaining clip will result in the need to replace your water heater.
Step 6: Insert the new thermostat
Inserting the new thermostat into the retaining bracket that holds the old thermostat in place will allow you to precisely position the new thermostat. Reconnect the wires to the relevant terminals by twisting them together. If necessary, you can refer to the photograph you took previously for guidance. Check to see that each wire is securely linked to the next. Check to see that the thermostat is securely attached to the water heater, otherwise the thermostat may not operate correctly. After that, adjust the thermostat to the temperature you like for the water.
These modifications may be accomplished with the use of a flathead screwdriver.
The following is an insider’s tip: If you intend to replace your heating element with your new thermostat, you will need to empty the water heater first.
Some people propose doing a quick change without draining the storage tank; however, I do not encourage this because any mistakes might cause harm to the interior of your house. Check out our post on how to empty your water heater, as well as additional water heater care advice.
Step 7: Reattach the cover panels
Now that you’ve completed the replacement, it’s time to seal everything up and double-check your work for mistakes. Remove the plastic protective cover and insulation and replace them with new ones. Reattach the outside access panels if they have been removed.
Step 8: Turn the power back on
Following the completion of the installation, return to the electrical box and re-energize the circuit breaker (if necessary). Hot water recovery will take around one hour to complete, but you should be able to use hot water within 15 minutes after turning on the faucet. Over the next several days, make sure to check on the water heater on a regular basis.
Water Heater Thermostat FAQs
Electric water heater thermostats are typically pre-set by the manufacturer to 110 or 120 degrees Fahrenheit, depending on the model. You have the option of increasing the temperature to the maximum setting, which is typically 150 degrees Fahrenheit, if necessary (65 degrees Celsius). The maximum water temperature setting should be no greater than 120 degrees Fahrenheit (48 degrees Celsius), since a higher setting might provide a scorching threat to small children and the elderly.
Should water heater thermostats be set to the same temperature?
In fact, the top and lower thermostats should both be set at the same temperature. The dip tube is responsible for delivering cold water to the bottom of the tank. Having consistent settings across the tank helps to keep the temperature consistent throughout the tank.
What would cause a water heater thermostat to burn up?
A malfunctioning heating element, a power surge, or just the passage of time can cause a water heater thermostat to burn up. When internal components of water heater thermostats wear out, they become faulty and fail. Even with regular electric currents, an older thermostat may experience failure. If the manual reset switch on your water heater thermostat does not work, the thermostat will need to be repaired or replaced. Replacement of both thermostats and heating elements should be done at the same time because if one of the heating elements is beginning to fail, it may cause the new thermostat to short out shortly after it is installed, which is not recommended.
Simply said, that’s the whole story! Water heaters aren’t too difficult to maintain, and replacing a thermostat can be completed in a matter of minutes if you know what you’re doing and have the right tools. The most important thing to remember while working with electrical equipment is to avoid taking shortcuts. Although it is possible to change your water heater thermostat in a short period of time utilizing the correct skills and tools, doing so is not recommended. DISCLAIMER: The information provided on HomeInspectionInsider.com is not intended to be professional guidance.
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Hot Water Heater Thermostat Testing
You can find detailed instructions for testing a hot water heater thermostat in the section below. Although this article is dedicated to dual element water heaters, single element water heater thermostats are examined in the same manner.
How to test a thermostat
The tests that follow will be carried out with the electricity turned on. You will require a multimeter, as well as knowledge on how to use it securely. If you want, you can test water heater thermostats with the power turned off. Go to the water heater thermostat and test it. Allowing someone to distract you while you are testing is not recommended. Make sure that no one comes close to the water heater until you’re through working on it. Please take the time to read the complete instructions before beginning.
Duel element residential water heater
At no point do both components heat at the same time. In the beginning, there is a tank of cold water. The higher element is responsible for heating the water in the tank’s top half. When the higher thermostat is satisfied, the upper element will be turned off and the bottom element will be turned on again to begin heating. It is not possible to do the following test if the water temperature is excessively high. This indicates that you may be dealing with a grounded element. If you want to learn more about grounded elements, check our water heater element testing.
You should first inspect the components before attempting to test the water heater thermostat.
Test hot water heater thermostat (upper)
Because neither element heats simultaneously, it is not necessary to use both components at once. In the beginning, there is a tank of cold water. The upper element is responsible for heating the water in the tank’s upper half. As soon as the higher thermostat is satisfied, the top element will be turned off and the lower element will be turned back on. If the water temperature is excessively hot, the next test will not be successful. A grounded element might be present in this situation. For additional information on grounded elements, see water heater element testing.
You should examine the components first before attempting to test the water heater thermostat.
Test water heater thermostat (lower)
Reduce the temperature of the top thermostat to its lowest setting. As you flip the thermostat dial, you should hear the thermostat turn off. If you don’t hear it, wait a few minutes for the water to warm up before continuing. Set the lower thermostat temperature to the maximum setting and check the voltage of the lower element on the lower element. If you have electricity at the element, you may let the water to warm up a little bit longer. Reduce the temperature setting on the thermostat. You should be able to hear it turn off.
If you don’t have any power at the element, proceed to the next stage in the process.
One multimeter probe should be placed on the top contact screw, and the second probe should be placed on the water tank (see pic).
If you are unable to obtain a reading, the top thermostat should be replaced.
If you have authority, go to the next step. One meter probe should be placed on the bottom contact screw, and another should be placed on the water tank. If you don’t have 120 volts, you need replace the thermostat on the bottom level.
Other pages you might be interested in.
A step-by-step instruction for changing an electric water heater thermostat is available online. Checking and replacing the gas valve/thermostat on a water heater is covered in this video. Water heater temperature – How to monitor and regulate the temperature of a water heater’s thermostat. Thank you for taking the time to look into hot water heater thermostat. Water heater thermostats: water heater home, water heater thermostats, hot water heater thermostats