How To Descale Rinnai Tankless Water Heater

How do I flush clean my Rinnai tankless water heater? (R)

It is possible for a tankless water heater to collect mineral build-up over time, which can corrode the walls of the heating chamber within the tank. For regular maintenance and cleaning of your tankless water heater, it is necessary to rinse those mineral deposits out at least once a year using a hose. Follow this straightforward procedure to guarantee that your tankless water heater performs and operates at peak efficiency. Please take the time to go through all of the directions before starting, as you’ll want to ensure that you have all of the essential items on hand for the procedure.




  • During the cleaning procedure, this stops cold water from entering the water heater and hot water from exiting the water heater. The water valves are comprised of three parts: a cold water valve (which is colored blue), a hot water valve (which is colored red), and a main valve, which is responsible for bringing water into your home.

4. Remove the purge port valve caps from the purge valves situated on each of the cold and hot water valves one at a time, taking care not to damage them.

  • The purge valves are distinguished by their little handles that mimic the letter “T.” In order to alleviate any pressure that has built up inside the valves and to avoid excessive hot water from pouring out during the cleaning process, this step must be carried out. Because there may be pressure when removing the purge port valve covers, it is critical to double-check that the hot water valve has been properly switched off for your safety. Make sure to handle each cap with care to ensure that the rubber sealing discs remain in place. These are required in order for your valves to operate correctly.

5. Connect a hosing line to each of the three valves in the system.

  • Tankless water heater hosing lines are available at any home improvement store that carries water heaters if the manufacturer did not include them with your tankless water heater. There must be adequate length between the water heater and the bucket for the hosing lines to be effective. Please refer to the tankless water heater manufacturer’s instruction manual, or contact the manufacturer directly if you require specific instructions on how to do this step. In certain situations, you may be required to utilize a sump pump and connect hoses in order to discharge and flush water from the tankless water heater’s cold and hot water valves during this operation.

Hosing lines are available at any home improvement store that sells water heaters if the manufacturer of your tankless water heater does not offer them. A bucket and a water heater must be accessible by hosing lines that are long enough to reach them. Consult the tankless water heater manufacturer’s instruction manual or directly contact the manufacturer for specific information on how to do this technique. In rare situations, you may be required to utilize a sump pump and connect hoses in order to discharge and flush water from the tankless water heater’s cold and hot water valves during this operation;

  • Given that the majority of your home’s drinking and bathing water is most likely routed through your tankless water heater, employing chemical cleaning solutions might be highly hazardous to your health.

8. To complete the flushing and draining operation, according to the directions provided in your manufacturer’s handbook. 9: When the flushing operation is finished, shut the purge port valves by twisting the T-shaped handles. 10. Disconnect and remove the hosing wires from each of the valves in the sequence listed. 11. Attach the purge port valve caps to the purge valves using the hose clamps.

  • Tighten the caps all the way down and securely. Take care not to overtighten or damage the rubber sealing discs that are contained within the caps, though.

12. Refer to your water heater’s owner’s handbook for specific advice on how to properly restart the unit.

  • If this is the case, you may need to rotate and open the cold and hot water valves so that they are parallel to one other and the main valve’s position.

If this is the case, you may need to rotate and open the cold and hot water valves such that they are parallel to one other and the main valve’s position;

  • Make sure to keep the water running until it flows consistently and there is no air escaping (you may recognize this by a slight sputtering sound). It might take up to 2 or 3 minutes for all of the air pockets to be expelled from the system.

How to Flush a Tankless Water Heater (Step-by-Step Procedure)

Please keep in mind that this content may contain affiliate links. This means that, at no additional cost to you, we may gain a small profit on purchases made via our links. Knowing how to clean a tankless water heatercan assist you in getting the most out of your investment in terms of efficiency and longevity. Consider the following steps in detail, as well as some helpful tools and crucial considerations.

The Importance of Flushing Tankless Models

Tankless water heaters are less expensive and more energy efficient to operate when compared to standard water heaters. They also demand significantly less maintenance and operating area.

That is why it is essential to understand first why and when it is necessary, followed by how to flush a tankless water heater, whether it is gas or electric. Examine how the naturally existing sediment in your water impacts the heater, as well as how to make flushing more convenient and safer.

Tankless Water Heaters and Scale Buildup

Anyone who has had a conventional water tank is aware with the necessity of flushing the tank on a regular basis in order to remove sediment. Tankless heaters are not an exception to this rule. Hard water includes minerals that can cause lime scale to build up on the surface of the water. An explosion from the accumulation is less likely with a tankless heater than with a tank model, but it can still result in some expensive complications with a tankless heater. The heat exchanger is particularly susceptible to scale buildup.

This can result in a considerable reduction in the lifespan of this component, as well as a large rise in your electricity expenditures over time.

How Often Should You Flush a Tankless Water Heater?

It is recommended that your tankless water heater be cleansed once a year to keep it operating at peak performance. However, the hardness of your water plays a role in this, and you may find that flushing twice or three times a year is preferable if your home’s water is of very low quality in this regard. To a certain extent, a sediment trap or a water softener can help with hard water.

Isolation Valves

It is critical that we explain isolation valves before proceeding with the rest of the processes. As the name implies, an isolation valve allows you to isolate (isolate) a segment of your pipeline’s liquid or gas supply without having to shut down the entire supply line (as would otherwise be the case). Essentially, the word is equivalent with the term “shut-off valve.” From your stove to your toilet, a wide range of objects in your home are equipped with some type of isolation valve for maintenance or emergency purposes, depending on the item.

In some cases, depending on the manufacturer and if a professional installed your tankless heater, an isolation valve may or may not be put on your tankless heating system.

Using Pumps and Flush Kits

A submersible pump is one of your greatest friends when it comes to flushing a tankless water heater. Instead of enormous volumes of water to sweep up and remove the sediment from a tank heater, a high-quality pump such as the91250 from Superior Pump can save you hours if not days of manual flushing and will save you money in the long run. Flushing will necessitate the use of a large bucket to contain the pump, since there is no easy drainage option available, as there is with a typical tank model, necessitating the use of a submersible model pump.

These kits often include everything you’ll need, including a pump, bucket, descaler, and hoses, among other things.

My favorite kit is made by My PlumbingStuff, and it not only works well and is simple to use, but it is also ecologically friendly down to the last component, making it the greatest tankless water heater flush kit in my opinion.

How to Flush a Gas Tankless Water Heater

Check the owner’s handbook for your water heater, since it may provide specific instructions on how to flush and descale the unit. Rinnai, Rheem, and Noritz are the three most popular manufacturers of gas tankless versions. For your convenience, we’ve included particular guidelines for each of the brands listed below:

  • Procedures for flushing a Rinnai tankless water heater, a Rheem tankless water heater, and a Notritz tankless water heater are all available online.

No matter what type of gas tankless water heater you have, there are a few steps in the flushing process that must be completed in the proper order, but they are all rather straightforward to complete.

Phase 1: Preparation

  1. Disconnect the electrical power source that is feeding the heater. Remove the access panel and check the terminal with a non-contact voltage tester to ensure that there is no longer any power coming through it. Discover where the gas isolation valve is located and close it. To prevent any water from entering the unit while you are working, locate the hot and cold shut-off valves and close them accordingly: To release any pressure, locate the hot water pressure relief valve, which should be located somewhere along the hot water line. Take cautious, because the hot water will be quite hot
  2. The service port for cold water and the service port for hot water will be separate. Hoses should be connected to both of these ports. Fill a five-gallon bucket halfway with water and submerge your submersible pump. The cold water pipe should be connected to your pump. Into the bucket, insert the free end of the hot water line
  3. Pour four gallons of undiluted virgin food-grade white vinegar into a pail and set it aside. In addition, Noritz recommends diluting one gallon of CLR with three gallons of water for heavy-duty applications.

Phase 2: Flushing

  1. Make sure that the hot and cold service ports are open and that the pump is running. Make sure the vinegar is allowed to flow through the heater for at least one hour (longer if the pump runs at less than four gallons per minute). As a result of this, the scale is broken down and the silt is flushed away. Turn off the pump and empty the vinegar into a trash can. Close the cold water service port and disconnect the hose that is connected to it. Open the cold water shutoff valve to let any residual vinegar to be flushed out through the second hose into your bucket for around ten minutes. Close the cold water shut-off valve on your faucet. Allow the water to drain completely before disconnecting the second hose. Close the hot water service port on the boiler. Remove the cold water intake filter as well as the hot water inline filter (if applicable). Remove any retained sediment by flushing the filters with water in a sink.

Phase 3: Cleanup

  1. Reinstall the filter(s) in a secure manner, and then turn off the hot and cold water valves
  2. Replace the access panel
  3. Turn on the gas shutoff valve
  4. And remove the access panel. The electrical supply should be reconnected.

How to Flush an Electric Tankless Water Heater

Flushing out an electric tankless water heater is a little different than cleaning out a gas tankless water heater, and some disassembly may be necessary. Generally speaking, Navien models are easier to understand, however some Takagi models require additional steps in order to properly place the water control valve.

  • Technique for flushing a Navien tankless water heater
  • Procedure for flushing a Takagi tankless water heater

Descaling an electric model is similar to descaling a gas model in that it may be divided into three stages.

Phase 1: Preparation

  1. Switching off the electrical power at the circuit breaker
  2. Close the cold water shut-off valve on your faucet. Open your taps to let any water that has accumulated in the heater to drain
  3. Close the shut-off valve for the hot water supply. Remove the access panel and check the terminal with a non-contact voltage tester to ensure that there is no longer any power coming through it. Disconnect the wires from the heating elements by removing the screws that hold them in place. Extraction of the heating element is accomplished by loosening the hexagonal brass top of the heating element in a counterclockwise manner
  4. Make a visual inspection of the heating components for evidence of damage. A broken element should be replaced as soon as possible. Storage of the heating elements in the cooper chambers of the heater to allow for cleaning of the heating elements
See also:  How To Restart Your Water Heater

Phase 2: Flushing

  1. Turn off the electricity at the circuit breaker
  2. Close the cold water shut-off valve on the faucet. Open your taps to let any water that has accumulated in the heater to drain out. Close the shut-off valve for the hot water supply
  3. If there is still power flowing to the terminal after removing the access panel, use a non-contact voltage tester to confirm that this is the case. Disconnect the wires from the heating elements by removing the screws that hold them together. The heating element should be removed by loosening the hexagonal brass top of the heating element in a counter-clockwise motion. Make a visual inspection of the heating components for evidence of wear and tear. When a cracked element is discovered, it should be replaced right away. In order to allow for easy cleaning, keep the heating components stored in the cooper chambers of the heater:

Phase 3: Cleanup

  1. Turn off all hot water faucets in your home. Close the cold water shut-off valve on your faucet. Clean any dirt from the cold water input filter by flushing the filter under a cold water faucet. Replace the filter in a secure manner. Power should be restored at the breaker once you close the access panel

How to Flush a Rinnai Tankless Water Heater

Rinnai tankless water heaters should be flushed at least once a year to avoid the accumulation of minerals and deposits that can form inside the heater. This buildup is created by hard water and might pose difficulties in the future by limiting the flow of water at both the input and outflow of the system. Fortunately, flushing a Rinnai tankless water heater is a relatively straightforward task that can be completed in as little as half an hour with a few simple tools. How to flush your Rinnai Tankless water heater yourself and save money while also learning a new skill is outlined in this step-by-step instruction manual.

How to Flush your Rinnai Tankless Water Heater

Cleaning a Rinnai tankless water heater begins with gathering all of the gear that will be required to do the work accurately and efficiently. These include, but are not limited to, the following:

  • Pliers with open jaws
  • A little pipe wrench Three (3) 5 gallon buckets (one with a lid)
  • Two (2) washing hoses
  • Three (3) 5 gallon buckets (one with a lid)
  • A submersible pump with a capacity of 4 gallons per minute is used. a gallon of white vinegar (four gallons)

It is necessary to turn off the tankless water heater as a first step in order to begin the operation. This is critical because if the water heater is turned on, the water heater will immediately begin pumping water. If the system is open at the time of this occurrence, the consequence will be a complete disaster. To proceed, close both the hot and cold isolation valves and attach the two water hoses to the service ports on both the hot and cold isolater valves. Step 2 This is done in order to allow the vinegar solution to flow through the valves and pipes of the plumbing system.

  • This will ensure that the vinegar solution is introduced into the system on a constant basis until the flushing process is done.
  • Because it will also be eliminating the minerals and deposits left behind by the hard water, the volume of solution pushed out of the system may be somewhat more than the amount of solution injected into the system.
  • Step 5After that, the vinegar is poured into a bucket and the submersible pump is turned on to start the process.
  • In most cases, the manufacturer recommends cleansing the system for at least 45 minutes, but the longer the better, especially in places with extremely hard water sources.
  • Rinnai tankless water heaters have components such as a blower fan, burners (for natural gas), and fins on the heat exchanger that help to heat the water.
  • Step 7After the flushing process is complete, the discharged solution is disposed of properly.
  • Once the discharged solution has been collected in the bucket, the bucket should be closed and sealed with the help of the lid.
  • Researching the local criteria is recommended by professionals as a starting point.
  • Using fresh water, four gallons of it is placed inside the bucket with the pump, and the fresh water is pumped through the system until it reaches the third discharge bucket.
  • Eighth step: Shut off the circulation pump and close the service port on the cold input to prevent water from entering.
  • As a result, the circulation of cold water into the heater will be reinstated.

Following that, the cold input valve is opened to allow fresh water to cleanse the system for a third time, but this time there is no need to collect the water that was previously collected.

FAQ Flushing Rinnai Water Heater

It is inherent in the design of tankless water heaters that they must be cleaned out on a regular basis. As a result of the minerals and deposits left behind by the hard water source used to feed the heater, this has occurred. A rough estimate suggests that around 80 percent of users in the United States are using hard water, which is utilized for everything from drinking water to taking showers. As a result, it is advised that users who have a tankless water heater system clean the whole system at least once a year.

Can I flush out my Rinnai tankless water heater myself?

Tankless water heaters must be cleaned out on a regular basis due to the nature of the device. This is due to the minerals and deposits left behind by the hard water source that is used to feed the water heater to cause this. Approximately 80% of users in the United States have hard water, which may be utilized for anything from drinking water to showering, according to some estimates. As a result, it is advised that customers who use a tankless water heater system clean the whole system at least once a year.

What is the best way to flush out a Rinnai tankless water heater?

This will most likely be determined by how skilled the individual performing the flushing is with equipment and how attentive they are to following guidelines. For example, the average do-it-yourselfer is likely to be familiar with common equipment such as wrenches, screwdrivers, and pliers, among other things. Flushing a Rinnai tankless water heater will only necessitate the use of a few simple hand tools as well as a few basic household items. For individuals who are new to the world of do-it-yourself, a tankless water heater cleansing kit may be a good starting point.

The manufacturer’s instructions for using the tankless water heater should be followed to the letter, since some manufacturers demand highly particular methods to avoid causing damage to the device.


Taking apart and disassembling a Rinnai tankless water heater is intended to be a reasonably simple process. Because no specific tools or expertise are normally necessary, the work may be completed effectively by the majority of householders. Important considerations include having the proper supplies on hand, properly following the manufacturer’s instructions, and, above all else, staying safe. Nick Lopresti is the creator of YourH2Home and a well-known specialist in the field of home renovation.

How to Clean a Rinnai Tankless Water Heater in 9 Steps

In the event that your heating or air conditioning system requires repair or replacement, we can link you with a dependable and cost-effective specialist in your region. There are several advantages to tankless water heaters, and the minimal danger of corrosion is undoubtedly one of the most significant. Tankless water heaters have a lesser danger of corrosion than traditional water heaters since there is no tank to collect the water. Overall, they are more reliable and convenient to maintain than the older systems that use tanks and other storage containers.

The development of sediment inside the tankless water heater’s heating chamber might ultimately damage the walls of the chamber.

A once-a-year flushing should be sufficient, however this may vary depending on your location’s water hardness and the kind of Rinnai tankless water heater that you are using.

What’s the proper way to clean a Rinnai tankless water heater?

Even while tankless water heaters are very simple to maintain, when it comes to cleaning, it is recommended that you follow the instructions to the letter. We’re still talking about a gadget here, therefore there can’t be any mistakes made throughout the cleaning procedure. When it comes to cleaning your Rinnai unit, follow these simple steps: 1. You should always start by turning off the electricity to the Rinnai tankless water heater. 2. It is necessary to turn off the circuit breaker if you have an electrical model.

  • 2.
  • There are three water valves that are connected to your Rinnai unit, which we will discuss.
  • It is also undesirable for the hot water to leak out of the faucet.
  • 3.
  • Pay attention to the purge valves, which should have small knobs that resemble the letter “T.” It is necessary to remove the caps from the purge valves very gently in order to release the pressure that has built up inside the pipes.
  • As you remove the purge port valve covers from the purge port, expect some pressure to build up.
  • ).

They are required in order for the valves to function properly.4.

Although not all manufacturers include the hosing lines with the unit, they are readily available at home improvement and water heater supply stores and online.

Examine the user handbook or even contact the manufacturer directly to find out how to flush the toilet properly.

It is perfectly OK to flush the water from both the cold and hot water valves at the same time.

It’s a simple procedure that requires just that you rotate them perpendicular to the location of the cold and hot valves.

Make sure the Rinnai tankless water heater is clean.

Cleaning the water heater, on the other hand, should be done using undiluted white vinegar.

Chemical solutions should never be used since they are hazardous to your health.

Rinnai tankless water heaters are diverse, and as a result, they may have varied flushing and cleaning requirements when it comes to maintenance.

Lastly, shut off the purge port valves.

Keep in mind that you must also disconnect and relocate every hosing line that is in close proximity to the valves.

It is necessary to tighten the caps tightly, but not excessively, to prevent them from falling off.


It is necessary to go to the manufacturer’s handbook once again in order to obtain specific instructions on how to re-start the tankless water heater.

They should be aligned in a line with the location of the primary valve.

Complete the cleaning procedure The hot water should be turned on gradually at a sink tap somewhere in your house.

Allow it to run until it is running regularly and there is no more air escaping.

After all of the air pockets have been released, it will take a number of minutes to complete the process.

We are confident in our ability to link you with a reputable service in your region that can repair, replace, or maintain your heating and air conditioning systems. Why not allow us to locate you a qualified professional?

Flushing Tankless Water Heaters – Tips on How to Flush Properly

Tankless water heaters should be flushed according to a simple step-by-step procedure. Don’t make educated guesses; learn when and how to flush your tankless heater. If you want to keep your tankless unit running at peak efficiency, heating efficiently, and lasting a long time, basic cleaning and draining away the limescale and sediment accumulation is the way to go. When compared to traditional tank-type water heaters, tankless water heaters do not store hot water. It is through the heat exchanger that the cold water is heated by the gas burner, which is often positioned beneath the heat exchanger.

Why flushing a tankless water heater is important

Simple step-by-step instructions for flushing tankless water heaters. Learn when and how to flush your tankless heater so you don’t have to guess. Cleaning and flushing off limescale and sediment accumulation is the best approach to ensure that your tankless unit continues to operate at peak efficiency, provides efficient heating, and has a long life. Instead of holding hot water in tanks, tankless water heaters use a storage tank to collect and distribute it. It is through the heat exchanger that the cold water is heated by the gas burner, which is typically positioned beneath the unit.

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Required tools

  • Small submersible pump
  • Garden hose (2 pieces) (or a kit)
  • Adjustable wrench
  • Plumber’s wrench
  • Screwdriver
  • Multimeter
  • Bucket

Instructions on how to flush a tankless water heater

As previously said, cleaning a tankless water heater is not difficult, and after it has been completed correctly, you must reset the fault code by turning off the electricity. (I’ll assume that isolation or service valves have been placed.) Here are the step-by-step instructions:

  • Turn off the power to your tankless heater (both the electricity and the gas)
  • Close the valves on the hot and cold water lines at the same time. Connect the circulation pump (such as a pond pump) to the cold water line by using the service (isolation) valve and connecting it to the cold water line (garden hose is OK). When the flushing solution is forced into the heater, the circulation pump is activated. In order to prepare the flushing solution, roughly 4 gallons of food-grade white vinegar should be used. Alternatively, you may purchase a delimer directly from the tankless manufacturer if necessary. The use of a cleaning solution that is non-toxic, non-corrosive, and biodegradable is highly suggested Empty the bucket and fill it with the cleaning solution (vinegar or delimer)
  • Connect the hose to the heater using another service valve and end it in the proper drain bucket
  • This is the final step. It is recommended that the drain and pump hoses end up in the same bucket and into the cleaning solution Activate both of the service valves on the hot and cold water supply lines. Turn on the circulation pump and let the flushing solution to circulate through the device for roughly one hour. Turn the pump off if it is running. Clean out the water heater by opening the shutdown valve on the cold water line (and closing the service valve between the pump and heater), allowing the cleaning solution to flow through the heater and into a bucket (approximately 5 min.) Open the shutdown valve on the unit and close the service valve that connects the heater to a bucket after that. Remove all of the hoses from the system. In addition, it is recommended that the in-line filter be cleaned. Continue to use the electricity and turn on the water heater

TheRinnaimanufacturer suggests that you follow the instructions outlined in the preceding literature. This is a safe and effective method of flushing tankless water heaters, which may be performed by the heater’s owner or a professional plumber. As an alternative, you may purchase a flush kit, which often contains a pump, hoses, hose adapters, a bucket, and descaler, among other things. The kits are compatible with tankless valves and may be quickly and simply installed. Tankless water heater manufacturers recommend draining the mineral deposits out of the system at least once a year, or more frequently if you live in a region where the water is very hard.


The yearly examination and maintenance of your tankless water heater is one of the most essential things you can do to safeguard your investment in the tankless water heater. Skipping yearly maintenance is the most common cause of premature failure, and doing so may result in the voiding of your guarantee. Proper inspection and maintenance will ensure that your heater operates at peak efficiency and for the longest possible time. Continue reading to discover how to properly maintain your Rinnai tankless water heater on an annual basis.

Annual Inspection Steps

Checking the error-code history of your Rinnai tankless water heater is the first step in doing an annual inspection on your tankless water heater.

This will notify you if something occurred that resulted in the occurrence of an error code that you were not previously aware of. The following is how you may look up the history of error codes:

  1. Push the Hot Water power button
  2. Press the down-arrow button
  3. And then press the power button again.

After you have completed this procedure, the device will indicate whether or not there have been any error codes. This will appear as a “e” followed by the code number shown on the unit’s display screen. If there are no problem codes, then you may go to the following stage without further delay. ‍

2. Remove the front panel of the water heater

The machine will notify you if there have been any error codes once you complete this procedure. The display on the unit will show a “e” followed by the code number, which will appear like this: The following step can be skipped if there are no error codes to be found. ‍ On either side of the front panel, there are two decorative strips that add to the overall appearance. Pulling the left side strip straight to the left and then pulling the right side strip straight to the right can help you get rid of them.

Remove the four panel screws from the back of the panel.

After you’ve completed this step, you’ll be able to remove the front panel.

It is important to emphasize that you should never attempt to remove the panel by force since you run the risk of breaking the tabs that keep it in place.

3. Inspect the Flame Rod

After removing the front panel, we can see inside the burner to ensure that the flame rod is functioning correctly, if necessary. In the center of the room will be a sight glass that will allow you to gaze through it to observe tubes within that are dispersing fire. When inspecting the heat-exchanger area, look for a very clean blue flame coming out of the flame rod into the heat-exchanger region, where water is heated as it passes through. You will be able to see a red flame erupting over the entire heat exchanger region, which is precisely what you want to see.

That the gas pressure is correct and precisely where it should be is indicated by this indicator.

4. Remove and clean the air filter screen

Because your Rinnai tankless water heater has a fresh air intake, a screen has been installed to prevent bugs and debris from entering the unit. The air filter is placed in the upper right corner of your unit and will move out in the direction of your body when you turn the unit on. Make sure there are no detachable objects and then reinstall it. If there is blocking material in the air filter, it may cause your unit to not have the right air-gas combination, which is why we do this. It may not function correctly as a result of this.

5. Remove and clean the cold water filterflush heater with vinegar ‍

It is possible to see a sequence of pipelines and valves underneath the device. For this stage, we are just concerned with the water input and outflow pipes, which are the two inner pipes that lead up into the unit from the outside. 1. Turn off the cold and hot water domestic water valves on the main water line. If you continue to follow those two inner pipes, you will eventually come upon a double-valve arrangement. Close both of these valves to prevent water from entering or exiting the heater, thus isolating it so that you may clean the cold water filter.

  1. Remove the lid from the cold water valve.
  2. Remove the cold water valve cap from the cold water intake pipe, which is located in front of the double-valve assembly.
  3. 3.
  4. A cold water filter is located at the point where the cold water intake line joins your unit.
  5. Remove the cold water filter and check it for any dirt or residue that may have accumulated.
  6. After that, replace the filter with a new one.
  7. That is how you will tell if it has been properly sealed and tightened.


If you haven’t previously, replace the cover on the cold water valve and turn off the blue valve that leads to the cold water valve.


Connect the service hoses to the hot and cold water lines, if you haven’t previously done so.

Pour the water from the heater into a 5-gallon bucket and allow it to drain for about 5 minutes to ensure that all of the water is removed.

Using the line that comes from the cold water input valve, connect it to the sump pump.

Turn on the hot and cold water valves on the service lines by pressing the on button on the valves.

For around 30 minutes, circulate the vinegar through the system.

Turn on the cold water supply at the main valve.

Allow the system to cycle for about 5-10 minutes to verify that all vinegar has been eliminated.

Remove the hose from the hot water service valve and turn off the hot water service valve. Caps should be replaced on both the hot and cold service ports. Turn on the hot and cold main water lines by turning the knobs on the faucets. After that, re-energize the heater.

6. Replace the front panel

Finally, in order to complete your yearly inspection, you will need to replace the front panel of your appliance. First, replace the front cover by screwing in the four screws that were previously removed from the cover. Replace the side strips on both sides once you have tightened them up. Well done, you have successfully finished the yearly maintenance of your Rinnai tankless water heater! If you have any concerns about any of these stages, please contact us or email us a photo with your queries, and we will respond as soon as possible.

What You Need to Know About Flushing a Tankless Water Heater

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  • Returning to the beginning

Why install a tankless water heater?

  • Tankless hot water heaters provide customers with an unlimited supply of hot water at a low cost. A tankless hot water heater should be installed by a licensed professional plumber so that you and your family can take back-to-back showers without ever running out of hot water.

Do tankless water heaters save money?

  • Yes! Tankless water heaters are more energy efficient and will save you money in the long term. A tankless water heater’s base price may be more than the price of a regular hot water tank
  • On the other hand, they can be up to 34 percent more energy efficient than a standard hot water tank and can last more than twice as long.

Tankless gas water heater or tankless electric water heater – which one?

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  • This is one of the most often asked questions when it comes to water heaters. People are sometimes forced to choose between natural gas and electricity. There are certain things to consider if you are given the opportunity to make a decision.

Thermoelectric Water Heater with No Tank

  • Gas units are designed to burn natural gas or propane, and the majority of manufacturers provide both a natural gas and a propane version of their product. The use of gas water heaters may be advantageous for big households with a high demand for hot water. These devices, on the other hand, require more maintenance and are less energy efficient.

Electric Water Heater Without a Tank

  • Electrical water heaters are less complicated to troubleshoot and consume less energy than gas water heaters. Electricity rates, on the other hand, tend to change less than gas prices.

What does it mean to winterize a tankless water heater?

  • Winterizing a tankless water heater refers to the process of prepping the unit for use in cold weather. Due to the fact that most manufacturers do not cover damage caused by freezing under their warranties, they may require a little additional attention during the colder months. Examine the following article to find out why winterizing your tankless water heater is vital and how to properly prepare your tankless water heater for the winter

What does flushing a tankless water heater mean?

  • When you flush a tankless water heater, you’re just cleaning it out with a descaling chemical, which eliminates any sediment or buildup that has formed.
See also:  Where Is My Tankless Water Heater

What happens if I don’t flush out my tankless water heater?

  • Mineral deposits may form over time. This might result in a clog within the unit, which could prevent regular heating activity from taking place. The temperature of your hot water may fluctuate, causing the system to overheat and reduce its effectiveness.

What are the benefits of flushing out a tankless water heater?

  • Reduces the likelihood of clogging: Tankless water heaters can accumulate mineral backing, which can be flushed out using a descaling chemical to reduce the likelihood of clogging
  • And Noise reduction: If your tankless water heater is creating noise, it is likely that there is a buildup of sediment within the tank. If the noise goes away on its own, it is possible that the accumulation has become so hardened that water is no longer able to travel through it efficiently. Acceleration of the heating process: The greater the amount of buildup in the tankless water heater, the longer it will take for the heat to move. Flushing your tankless water heater on a regular basis might help it operate at peak efficiency. Equipment lifespan: By flushing out the tankless water heater with a descaling solution, you are extending the life of the tankless water heater. Cost: If your tankless water heater is clogged, it makes it more difficult for the water to move through, increasing the amount of energy required to create hot water, resulting in higher costs! Flushing on a regular basis boosts water flow and has the potential to save expenditures dramatically.

How often should I have my tankless water heater flushed out?

  • Tankless water heaters should be cleaned out once a year to twice a year, depending on usage.

Why should I have my tankless water heater flushed out so regularly?

  • The water in the areas surrounding Rochester, NY that are supplied by the Monroe County Water Authority is somewhat hard, which means that tankless water heaters must be cleaned out more frequently than in other places.

What is hard water and how does it impact my tankless water heater?

  • Water hardness is a measure of the amount of minerals present in a body of water. Monroe County’s water is regarded to be somewhat hard by most standards. In one gallon of hard water, it comprises between 5.6 and 7.6 grains of calcium carbonate. The mild hardness of the water in Rochester, NY and Monroe County means that homeowners do not require a water softener
  • Nonetheless, flushing out your tankless water heater using a descaling solution is extremely vital owing to this.

Do I need a professional for flushing out my tankless water heater?

  • Yes! It’s usually a good idea to get a licensed professional plumber for any plumbing emergency.

Do I need to call a plumber near me just to have part of my tankless water heater cleaned?

  • Yes! If you are experiencing problems with your tankless water heater, it is possible that a specific section of it has to be cleaned. A tankless water heater is made up of a number of different pieces, therefore it is always advisable to consult with a certified professional plumber for assistance with your water heater needs.

What brands of tankless water heaters does Pride Plumbing carry?

  • When it comes to tankless water heaters, we at Pride Plumbing of Rochester only provide the highest-efficiency models that are helpful to your house. The Navien brand of tankless water heaters is one that we sell
  • Navien tankless water heaters are energy star rated, which means that they save both energy and money over time. These tankless water heaters may also be used in conjunction with the RG E refund, which can result in a savings of up to $200! These water heaters also have a sleek appearance and are 80 percent less in size than standard tank water heaters.

Are you thinking, “who is a plumber near me that can help with my tankless water heater?”

We are here to assist you! Call (585) 271-7150 to speak with your neighborhood plumber, or make an appointment online. Take advantage of our promotion to save $250 on a tankless hot water heater purchase.

How to Flush a Tankless Water Heater and Clean the Air Intake Filter

Water heaters that do not have tanks will accumulate calcium and debris on the heating components and filters within the unit. It’s critical to cleanse your system with food-grade white vinegar at least once every 12 to 18 months to keep it running smoothly. The performance and life of your water heater will be extended if you do this straightforward maintenance. This is also a good opportunity to remove and clean the air filter inside the tankless water heater while you’re conducting your regular cleaning.

However, this procedure may be used to any tankless water heater so long as you can identify the necessary components on your machine.

Step 1: Gather Your Materials

Water heaters that do not have tanks will accumulate calcium and debris on the heating components and filters within the unit. At least once every 12 to 18 months, it is necessary to cleanse the system with food-grade, white vinegar. The efficiency and life of your water heater will be extended if you do this basic maintenance. While you’re flushing the tankless water heater, it’s a good idea to clean the air filter that’s within the unit. If you are using a Navien tankless water heater, this instructable will teach you how to flush it.

You should note that the knobs under your tankless water heater are color coded for your convenience.

If the levers are parallel to the pipe, it implies it is turned on, and if they are perpendicular, it means it is turned off.

As a result, the gas (yellow handle on the right side linked to the silver pipes), the central yellow handle, the cold water input (blue), and the hot water outflow will all be turned off (red). During this time, you can also unplug your unit from the power outlet if necessary.

Step 3: Unscrew the Cold Water Service Valve

A service valve is located just above the red and blue levers. The service valve can now be opened once the levers have been rotated such that they are perpendicular to the pipe and the water has been turned off to the tankless hot water heater. But first, gather your stuff and get ready to start. Please keep in mind that there is an external pump that is hooked to the wall near the ground level. The electronic components of the gadget are visible via the vents located at the top of the device.

  1. Make sure you have a bucket ready to capture any excess water that may come out of the faucet.
  2. Even though it is a small amount, you do not want it on your garage floor.
  3. Make sure one end of the hose is inserted into the bucket so that when you remove the service valve cap, you may try to plug it into the opening fast and divert part of the water into the bucket.
  4. Our water heater is only set to 120 degrees Fahrenheit, which I believe to be the case.
  5. The water that comes out of the hot water service valve should not be too hot if you have been taking hot showers, using the dishwasher, and running the washing machine just before doing this.
  6. If the water is hot, you may want to unscrew the service valve carefully so that you don’t burn yourself while doing so.
  7. It occurred to me at that point that the water was not hot, but rather warm, so I completed unscrewing the service valve, plugged in the hose, and allowed the water to drain into a pail.

Step 4: Setup Your Vinegar and Pump

The hoses you used to connect to the service valves in the previous step should be ready to use for this step by now assuming you did so in the previous step. Make sure you empty your 5-gallon bucket of any water that has accumulated in it from the service valves. Approximately 4 gallons of food-grade white vinegar should be added to the bucket. I purchased a generic brand from Safeway, and the total cost for four gallons was $16. Attach the line that connects to the cold water (blue) service valve to the sump pump’s top outlet.

  1. Do not connect the pump at this time.
  2. Because there is no on/off button, it will automatically turn on as soon as you connect it into a wall outlet.
  3. It is not necessary to screw it into the pump; instead, it should be put loosely in the vinegar bucket.
  4. Connect the pump to the electrical outlet as soon as possible.

At the very least, you’ll keep it like way for at least 60 to 90 minutes. The handbook says 45 minutes, but I assumed because it had been so long, I’d simply leave it on for a little longer.

Step 5: Cleaning the Air Intake Filter

Additionally, while the vinegar is being circulated, you should wipe out the air intake filter. If you’ve been noticing an error message on your screen that says “027,” you’re not alone. This indicates that you should clean the air intake filter. The tankless water heater’s air intake filter is situated within the tankless water heater. Don’t worry, it’s not difficult to get to, but you must first remove the tankless water heater face plate before you can get to it. A total of four screws hold it all together.

  • It is necessary to first remove all of the screws from the face plate before lifting upwards and releasing the hook that connects the top of the face plate to the top of the tankless water heater frame.
  • Then you’ll want to look for the single screw that holds the air intake filter in place.
  • As soon as you have unscrewed the one screw that holds the air filter, pull the whole thing slightly towards you and then slant it slightly so that it will slide over the motor, and you have successfully removed the air filter.
  • Afterwards, I just strolled over to my water spout outside my garage and ran it on full blast, thoroughly rinsing the filter.
  • Replacing the tankless water heater face plate and allowing the pump to continue to operate for the remaining 60-90 minutes is recommended.

Step 6: Rinse Your Tanless Water Heater After the Vinegar Treatment

Now that the vinegar has been pumped through the tankless water heater for 60-90 minutes, it’s time to rinse the vinegar out of the tankless water heater. Remove the sump pump from the wall outlet by unplugging it and lifting it out. Allow it to drip into a vinegar bucket and save it aside for later usage. I made the decision to put the vinegar into the toilet rather than on the grass or plants in order to prevent hurting the plants or grass. Now that you have a bucket that is empty, place the bucket back beneath the tankless water heater to keep it there.

  1. Replace the service valve cap with a screwdriver and tighten it.
  2. Allow around 4-5 litres of water to flow through the tankless water heater and out the hot water line into a bucket by releasing the lever controlling the cold water intake.
  3. After everything has been completed, it is necessary to inspect the water filters.
  4. These may be unscrewed with just your fingers if necessary.

After removing the filters, make sure to thoroughly check the area for debris. Reinstall the filters by thoroughly rinsing them with water and screwing them back in.

Step 7: Reattach Everything and Turn It on – Moment of Truth

Following the complete descalement and cleaning of your tankless water heater’s air intake filter, it is time to reassemble everything. Before opening any valves, double-check that all service caps are securely fastened. After you’ve made certain that everything is properly sealed, you may begin opening valves. I’d start with the cold water valve and work my way up from there. You’ll hear the sound of water streaming inside your body. After that, turn on the hot water faucet. After that, the gas and central circulation valves are opened (yellow).

As soon as the display turns on and the machine begins to cycle, you may observe various symbols on the screen.

I hope everything goes as well for you as it did for me.

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