Navien Tankless Water Heater Maintenance [A-Z Guide]

From my experience of working on many heaters, I can tell you that the main Navien tankless water heater maintenance tasks are:

  • Cleaning the exterior of the water heater.
  • Draining the water heater.
  • Cleaning the air intake filter.
  • Flushing the heat exchanger.
  • Freeze protecting the heater.
  • And more.

Keep on reading this guide to learn more about all these maintenance tasks in detail. I’ll also explain how often you should do each of them and share some tips on maintaining the Navien boilers as well. So, let’s dive in!

navien tankless water heater maintenance

I’ll talk about all the things you need to do so that you can maintain your Navien tankless water heater in this section. Some will be easy and some will require more work. So, let’s go through them one by one.

01. Cleaning The Exterior Of The Water Heater

You have to clean the heater as well as the area around it from time to time to keep it in good condition. Navien tankless water heater cleaning is a simple job. You can do it on your own.

How To Clean Navien Tankless Water Heater?

First of all, turn off the power to the water heater and disconnect the power supply. The water heater could still be hot for a while after you’ve turned it off. So, don’t start working on it right away. Instead, wait for some time until the heater cools down, and then proceed to clean it.

Start by cleaning the surrounding area of the water heater. If it’s dirty, the heater will also get dirty. You can take a piece of cloth and clean it. Then, you’ll have to clean the water heater itself.

The front panel of the water heater is moisture resistant but it’s not waterproof. So, you can use a damp cloth to clean it but using a soaking wet cloth would be too much.

If there are any stains in the water heater, you can use a non-acidic and non-abrasive cleaner to remove them. Try to keep the heater as dry as possible when you clean it. You’ll be fine as long as you use a damp cloth.

02. Draining The Water Heater

You’ll have to drain your water heater at periodic intervals to perform maintenance tasks on it. It’s something you’ll have to do to clean the water inlet filter and flush the heat exchanger.

You’d also have to drain the water heater to keep it from being frozen when it’s not used for a long time. But don’t worry, there’s no need to panic. I can tell you from my personal experience that draining the water heater is one of the easiest tasks you can ask for. Follow these steps to do it:

Step 01: Turn Off The Electrical Power

Start by placing a bucket under the water heater. It’ll help you to catch any residual water that comes out of it later. Turn off the power supply to the water heater by pressing the power button. Unplug the heater from the power outlet.

press the power button of navien tankless water heater

Step 02: Shut Off The Gas & Power Supply

Close the gas valve of the water heater to shut off the gas supply. Keep in mind that the gas valve is open when it’s parallel to the gas line. But it’s closed when it’s perpendicular to the gas line. Here’s a picture to help you out:

turn off the gas supply  of navien tankless water heater

Close the water inlet supply valve under your water heater. If you can’t find that valve or haven’t installed it, you’ll have to turn off the main water supply valve in your house.

Open all the hot water faucets in your house. The water that would remain on the plumbing lines will come out automatically when you do that. Remove the circulation filter from the bottom of your water heater if your unit has it.

Step 03: Remove The Water Inside The Water Heater

Open the drain plug of the water heater and remove the cold water inlet filter. The water inside the water heater will start to come out. Make sure the bucket is placed right under it and it’s catching the water.

You surely don’t want any water spilling when you’re draining it from the heater. When the water is completely drained from the water heater, put the recirculation filter back in its place.

Then, put the cold water inlet filter in its place and close the drain plug. That’s how you can drain the water from the water heater. Then, you’ll have to restore the water in the water heater after you’re done with the maintenance task.

Get rid of the water in the bucket and open the cold water supply line. Let the water go through the hot water faucets to purge the air from the lines. Then, close the hot water faucet and restore the power supply to the water heater.

03. Cleaning The Air Intake Filter

The air intake filter of your Navien tankless water heater has a crucial job. It catches the dirt that comes through the air intake and makes sure that only clean air goes to the water heater.

In the process, the air intake filter gets dirty. You can find all sorts of things in the air intake filter including leaves, insects, and wasps. The good news is that you can easily clean the air intake filter.

How To Clean Navien Air Intake Filter?

One of the easiest DIY jobs to do on a Navien tankless water heater is to clean the air intake filter. I’ve done it hundreds of times in my own water heater and others. I’ve broken down the process into three simple steps. Follow them to clean the air intake filter in your Navien tankless water heater.

Step 01: Expose The Air Intake Filter

Press the power button and shut off the power supply to the water heater. Then, disconnect the water heater from the power outlet. Take off the front cover of the water heater.

Step 02: Clean The Air Intake Filter

You’ll see a screw located at the top left of the water heater when you take off the front panel. That’s the screw that holds the air intake filter in place. You’d have to undo that screw to remove the air intake filter.

removing the air intake filter of navien tankless water heater

Once you remove the screw, you’d be able to pull out the air intake filter. Clean it in running water. If there’s any piece of dirt that’s hard to get out, you can use a toothbrush to get rid of it.

If you’re having difficulty cleaning it, you can separate the filter from the plastic assembly. Hopefully, you’ll have an easier time cleaning it that way. Keep scrubbing the filter until you’re happy that you’ve got all the dirt out.

Step 03: Install The Air Intake Filter Back In

Let the filter dry out completely. Connect the plastic assembly and the filter back together if you separated them before. Put the air intake filter into its position in the water heater.

Make sure the air intake filter sits in place and secure its position by tightening the screw you removed earlier. Put the front cover of the water heater back together. Restore the power supply to the water heater and use it.

04. Flushing The Heat Exchanger

The heat exchanger will develop sediments in it with time. That’s because the water you use isn’t one hundred percent clean. If you live in an area with a hard water supply, the heat exchanger will get filled with sediments faster.

So, you must flush the heat exchanger from time to time.

flushign the heat exchanger of navien tankless water heater

Flushing the heat exchanger will get rid of the sediments built up inside it. If you don’t flush your heat exchanger at the required intervals, the heat exchanger will eventually be damaged. So, flushing the heat exchanger is the most important maintenance task you need to follow.

i) How To Flush Navien Tankless Water Heater?

Flushing the tankless water heater is an easy process. You can follow these steps to do it:

  1. Turn off the water heater and disconnect it from the power supply. Close the water inlet and outlet valves located at the bottom of your water heater.
  2. Connect the first end of one hose to the hot water line and the first end of another hose to the cold water line.
  3. Leave the other end of the hose connected to the water line in the bucket. Connect the other end of the hose of the cold water line to the recirculation pump.
  4. Place a cleaning solution in the bucket and turn on the recirculation pump. Let it run for 45 – 60 minutes to get rid of the sediments in the heat exchanger.
  5. Close the service valves, turn on the shutoff valve, and let clean water run through the heater for a few minutes.
  6. Disconnect all the hoses from the water heater and restore the power supply to it.

So, that’s how easy it is to flush the heat exchanger on your own. Hopefully, you’ll be able to follow along and have no difficulty in completing this job.

ii) How Often To Flush Navien Tankless Water Heater?

Flushing the heat exchanger at the right intervals is crucial to keep your water heater working properly at all times. But how often you need to flush the water heater depends on the level of the hardness of your water.

At the very least, you should do it at least once every other year. Keep in mind that it’s the bare minimum. You’ll be fine doing that if your water heater is fairly new and you live in an area without a hard water supply.

But if you have an old water heater or the level of water hardness in your area is high, you may even have to do it once every six months. But you may also get by by doing it once a year. It all depends on how much scale builds up in the heat exchanger.

Navien recommends doing the flushing procedure once every year as a general guideline. But depending on your situation, it could be anywhere from six months to two years.

You’d have to test the water to find out more about it. There’s a lot more you need to know about flushing the water heater. Luckily, I’ve compiled a detailed guide on how you can flush the heat exchanger in your water heater.

You’ll find all the information about this topic in detail there along with a list of the tools you’ll need. Check it out to become a master of the flushing process in your Navien tankless water heater.

iii) Can You Flush The Water Heater With Vinegar?

If you don’t have a cleaning solution available, you can use food-grade white 

vinegar instead of it. It’ll have the same effect as any other cleaning solution. The main thing is to recirculate the heater for a long enough period that the heat exchanger cleans.

As long as you make sure of that, it doesn’t matter if you use white vinegar or any other solution. Again, you’ll find detailed information on flushing in the guide I mentioned earlier.

05. Cleaning The Water Inlet Filter & Recirculation Inlet Filter

When you have to clean the water inlet filters, you’d have to drain the water heater first. You should already know how to do it as I’ve shared that earlier in this guide. Once you remove the water from the heater, you’ll be able to take off the filters easily.

water inlet & recirculation filter of navien tankless water heater

The recirculation filter is only there in the “A” type of tankless units. So, don’t worry about it if you don’t have such a unit. After you remove the filters, clean them under running water to get the dirt out of them.

Sometimes, you’d have to scrub the dirt out if it’s stuck in the filter. You can use a toothbrush for this job. Once you’re happy with the cleaning results, you can reinsert the filters in their place.

Then, tighten the filters to secure them in their respective positions. Let the water heater get refilled with water heater. Then, you can continue to use the water heater normally.

06. Protecting The Water Heater From Freezing

It’s a very important maintenance task that’s often overlooked by many people. Keep in mind that the Navien warranty becomes void if your water heater gets damaged due to freezing.

Negative pressure in the building can lead to back drifting and that can damage your water heater. It’s the installer’s job to make sure that there’s enough air to prevent that situation.

It’s also up to the owner to make sure that the heater is protected against freezing conditions. That’s why Navien doesn’t offer any warranty for these types of damages.

I suggest that you use a direct vent exhaust and intake system to protect the water heater from freezing. Both these pipes should be connected directly and firmly to the vent collars on top of the water heater. They should lead outdoors. Such a venting system is crucial in reducing the air movement in the heater.

Navien water heaters are designed to be installed both indoors and outdoors. However, it could be a better idea to install the water heater indoors if you live in an area where the temperature is freezing.

You can also keep the water heater in optional recirculation mode for freeze protection. It’ll minimize the chances of the water heater freezing even if there’s no direct venting.

I’ve already shared the right practices you should follow to protect the water heater from freezing. But as a bonus, here are a few more tips to prevent the water heater from being frozen:

Don’t Unplug The Water Heater From The Power Outlet

Sometimes, you’ll have to unplug the water heater’s plug from the power outlet to do some maintenance work. When you unplug the water heater, plug it in as soon as you’re done with the maintenance job.

Apart from when doing maintenance tasks, make sure that the water heater remains connected to the power outlet at all times. It’s important because the freeze protection feature of the water heater only works when there’s an electric supply.

It’s not so important if the water heater is turned on or off. If the heater is connected to an electrical supply, the freeze protection will work perfectly.

Don’t Close The Gas Valve

If you turn off the gas valve for an extended period, it’ll limit the freeze protection ability of your water heater. So, freezing damage can happen to your water heater if there’s an interruption to the gas supply.

Of course, you’d have to turn off the gas supply of the water heater at times for maintenance. That’s completely fine. But make sure that you turn the gas supply right back on as soon as the maintenance is done.

Sometimes, you may go on vacation. Understandably, you wouldn’t leave the gas valve in those situations. And you don’t have to. Just make sure you drain the water heater before you head out for a long time.

What To Do If Water Heater Is Frozen?

Everything that I’ve talked about so far were prevention steps to keep your water heater from being frozen. But sometimes, it can be a little too late and you may realize the issue after the heater is already frozen.

If no hot water would flow from the heater and you don’t know what to do in that situation, I got you covered. Follow these steps to fix this issue and continue to use your water heater:

  • Turn off the power to the water heater immediately and turn off the gas valve.
  • Open the hot water faucet that’s located the nearest to your water heater.
  • Place a hair dryer or blower to heat up the heat exchangers of the water heater. You can also use a portable electric heater instead of a hair dryer.
  • Inspect the faucet from time to time to see if any water’s flowing from it.
  • The water should start flowing after a while. Check for leaks when that happens. If the water leaks from anywhere, there’s a problem with your water heater and you need to get it fixed.

If there are no leaks, then you’re lucky because it’s likely that the water heater hasn’t suffered any critical engine at that time. But remember that prevention is better than cure. So, follow the right practices to keep the unit from freezing.

07. Draining The Condensate Water In The Siphon

Navien makes both condensing and noncondensing water heaters. In the non-condensing units, no condensation is formed. But that’s not the case in condensing units.

You’ll have to remove the condensation in those units from time to time. Place a bucket to catch the condensate water. You’ll have to remove the retaining clip and twist the cap bottom of the siphon. Doing that will remove the siphon cap and start draining the condensate water.

condensate siphon of navien tankless water heater

Once the water is drained, you can clean the siphon. Then, put the siphon cover back on and restore the retaining clip. The final step is to pour water into the exhaust connection to refill the siphon. You’re all done with this process when you do that.

How Often Should You Maintain Or Service Navien Tankless Water Heater?

Now you know all about the maintenance tasks on your water heater. But you may be confused as to how often you should do each of them. Unfortunately, there’s no straight answer. That’s because it largely depends on the area where you live.

For example, if you live in an area with a hard water supply, sediments will build up in the heat exchanger faster. So, you’d have to flush the heat exchanger more often than in areas with a softer water supply.

Similarly, if the air coming from the vents is clean, your air intake filter won’t get dirty soon. But if you live somewhere where the air is dirty, the air intake filter will get clogged soon. So, you’d also have to clean it more often.

Hopefully, you get the idea by now. With that in mind, here’s a general guideline of the frequency with which you should do all the maintenance tasks:

Maintenance TaskMaintenance Frequency
Cleaning the exterior of the water heater.Once every month as it’s a simple job.
Draining the water heater.Only needed when doing a maintenance job that requires draining. Other than that, there’s no need to do it.
Cleaning the air intake filter.Once every 3-4 months.
Flushing the heat exchanger.Once or twice a year depending on the level of hard water.
Cleaning the water inlet and recirculation filter.Once every six months.
Protecting the water heater from being frozen.Only needed when you’re going on vacation. Apart from that, all you need to do is to make sure that the heater has a power and gas supply at all times.
Draining the condensate water in the siphonOnce every three months.

Keep in mind that you should only use the above information as a general guideline. If you see that cleaning as often as mentioned makes your heater work well, you can stick to that.

But if you see that your heater gets too dirty between the recommended intervals, you need to ramp it up. Use your judgment in figuring out how often you need to do the maintenance tasks using the above table as a guideline.

What Is The Cost Of Maintaining Navien Tankless Water Heaters?

Many of the maintenance tasks I talked about don’t involve any cost. For example, you wouldn’t need anything other than a piece of cloth to clean the exterior of the water heater.

Similarly, you’d only require a toothbrush and running water to clean the air intake and water inlet filters. The cost of a toothbrush is trivial and you can also utilize a used one. So, there’s no need to worry about them.

The main maintenance task that costs money is flushing the heat exchanger. If you don’t have one already, you’d need to buy a flushing kit. You can usually find those kits in the $100-$150 price range.

But even that is a one time investment. The most important thing you’d need from that kit is the recirculation pump. Then, you can just get the cleaning solution when you run out of it for your future heat exchanger flushes.

How To Maintain A Navien Condensing Combi Boiler?

The maintenance tasks on a boiler aren’t too different from that of a tankless hot water. They work similarly and therefore, require similar maintenance. The practices that are common for boiler and tankless water heaters are:

  • Cleaning the exterior of the boiler.
  • Draining the boiler.
  • Cleaning the water inlet filter.
  • Protecting the boiler from being frozen.
  • Cleaning the air intake filter.

You already know how to do these things as I’ve discussed them for a tankless water heater. The one additional thing you’d have to do for a boiler is to clean the strainer on the space heating side.

The most obvious sign indicating that you have to clean the stainer is if the space heating performance is reduced. You can follow these steps to clean the strainer on your Navien combi boiler:

  1. Drain the space heating side of the boiler.
  2. Remove the clip and take out the strainer.
  3. Rinse the strainer in clean running water after you remove it.
  4. Put the strainer back in its original place.
  5. Tighten the connection and make sure that the strainer is safely held in place.
  6. Refill the boiler and check the water heater for operation.

So, that’s how easy it is to clean the strainer. Check the boiler area, vent piping, air piping, and condensate drain from time to time as well. If you do that and take care of the problems as you see them, you can expect your boiler to last for a long time.

How To Do Preventive Maintenance Of Your Navien Tankless Water Heater?

You can increase the chances of your water heater and boiler lasting longer by maintaining them well. I’ve already shared the top things you can do to make sure your heater stays in top condition.

On top of that, I’ll share some additional tips to help you take care of your heater and boiler even more. You can follow them to detect problems with your heater early on and come up with the fixes. Here they are:

i) Inspect The Interior From Time To Time

I’ve already talked about cleaning the exterior of your water heater. But you should always check the interior at periodic intervals. Take off the front cover and inspect the condition of the internal components.

checking the interior of navien tankless water heater

If you see any sediments or dirt there, you can vacuum that area to remove those obstructions. Make sure that the area around the heater is free from any combustible materials as well to avoid accidents.

ii) Inspect The Piping For Leaks

As you continue to use your water heater, minerals can build up in different sections of the pipes. Such parts can get corroded with time and develop leaks. 

So, the water heater will have to work harder to keep up with the hot water demands. Eventually, the heat exchanger can get damaged due to this issue. If you locate any leaks in the pipes, fix them immediately.

iii) Check The Flue Vent System And Air Piping

You can inspect the vent system with your eyes and look for any signs of blockage in them. Especially, check the joints to see if there’s any leakage.

If you detect any weak spots, replace them soon to keep the problem from escalating. Make sure the air intake pipe is connected securely and free from any obstructions. If you find any dirt in them, remove them.

iv) Check Expansion Tank And PRV Periodically

Expansion tanks are important as they regulate the pressure and the temperature of the hot water. It’s a good idea to inspect their condition at least once annually as recommended by the manufacturer.

It’s also crucial to check if the pressure relief valve is operating properly from time to time. You can manually lift the lever of the valve to make sure it has proper flow.

pressure relief valve of navien tankless water heater

However, make sure that the water coming out of it will discharge in a safe area to protect yourself from scalding. You should operate it manually at least once every year.

Keep in mind that the valve can naturally become corroded with time. You won’t be able to detect that without removing and inspecting the valve. So, it’s a good idea to get the PRV checked by a licensed plumber at least once in every three years.

If there is any issue with the PRV or it doesn’t sit properly, it will have to be replaced. If the relief valve is weeping, then you’ll have to confirm whether the valve is faulty or the system has too much pressure. Then, you have to take the corrective actions to fix the issue.

v) Inspect Ignition And Flame Detector Electrodes

The electrodes in the flame rods will become dirty with time as you continue to use your water heater. So, it’s a good idea to check them. You can remove them from the heat exchanger to inspect their condition.

flame rods of navien tankless water heater

Clean the electrodes when they get dirty. If you can’t get the dirt out, you’ll be better off replacing them. When you replace them, make sure you position the gasket correctly and that it’s in great condition.

vi) Check The Wiring

You’ll run into a lot of problems with your boiler or heater if the wiring connections come loose. So, it’s a good practice to check up on the condition of the wires from time to time.

Check the ground wire and make sure it’s connected properly to the casing. Inspect the continuity of the wire and replace it if needed. Inspect the internal wiring of the heater as well.

If any of the connections have come loose, you can tighten them. If any of the wiring seems corroded or damaged, you need to act fast and replace them.

vii) Inspect The Burner Flame

You can check the flame of your Navien tankless water heater or boiler through the observation window. Ideally, you should see a healthy blue flame. Seeing a fire that’s too high or low is bad for your water heater.

The most likely reason behind that is obstructions in the venting system. Check the air intake system and make sure there are no obstructions in there. Take out the air intake filter as well and clean it.

How To Service A Navien Tankless Water Heater?

The most important thing when it comes to servicing your water heater is to clean and descale the water heater. The heat exchanger gets clogged with time. So, it’s not something you should overlook.

You should also take the front cover of the water heater off from time to time and inspect it. If there’s any dirt or loose components, you can immediately take corrective actions.

As long as you follow all the tips shared in this maintenance guide, you’ll be fine. You already know about how often you should service the water heater if you’ve followed this guide so far.

How To Clean Navien Tankless Water Heater?

Cleaning your water heater properly is an important part of maintaining your water heater well. You need to clean the water heater from both outside and inside to keep it in mint condition.

First, let’s talk about the outside of the heater. You need to clean it with a damp cloth. Not doing so will make your heater dirty on time. Another important thing you should do is to keep free space between the objects and the heater. Otherwise, that could lead to unfortunate incidents.

When it comes to cleaning inside the water heater, you’d have to take the front panel off first. Then, take off the air intake filter and clean it. It’s highly likely that you’d find some debris in there.

Then, you’d also have to drain the water heater. Once you do that, you’re ready to clean the filters at the bottom of the water heater. You’d also have to flush the heat exchanger from time to time. By now, you should already know how to do these things as I talked about them in detail in this guide.

What Is The Relation Between Tankless Water Heater And Water Softener?

There are water filters in your tankless water heater to improve the quality of water that enters your water heater. But it can only do so much. If you live in an area with a hard water supply, the heat exchanger in your water heater will be clogged. Eventually, it can also get cracked and be damaged.

But what exactly is hard water? The water that flows through the pipes contains impurities. You may think that there’s nothing and you get 100% fresh water but that’s not the case. Different minerals flow along with the water.

When the number of minerals is low, it’s called soft water. But when there are too many minerals in the water, that’s hard water. The problem with minerals in water is that they’ll settle on the heat exchanger. And they’ll begin to corrode the heat exchanger.

So, it’s important to protect the heat exchanger from that. The first thing you can do to prevent that is to flush the heat exchanger at regular intervals. But that’s a time-consuming process. And while it’s a great curative measure, it doesn’t address the issue that you have a hard water supply to begin with.

That’s where something like a water softener can come in really handy. It reduces the hardness of the water and protects all the equipment that used to be affected by the hard water supply.

Should You Install A Water Softener With A Tankless Water Heater?

There are many brands of tankless water heaters and none of them say that it’s a must to install water softeners along with them. But if you live in an area with a hard water supply, it’s something worth considering.

Installing a water softener can have numerous benefits. Here’s a quick look at a few of them:

i) Increase the Lifespan Of Your Water Heater

This guide is dedicated to making sure that you get the most out of your water. That’s why I wholeheartedly believe you should install a water softener to increase the lifespan of your water heater.

Installing it will ensure that less minerals get into the heat exchanger of your water heater. So, it won’t have a severe scale build-up and last longer.

ii) Get Hot Water Even Faster

The presence of minerals in hard water makes them attracted to the pipes and metal parts. It all happens fast and the speed of the water transfer is slowed down by a little bit.

A water softener will reduce these minerals by a great deal and increase the efficiency of water movement. So, you’ll get hot water faster when you need it.

iii) Reduce Energy Bills

The water heater will have to work harder to heat the water when there are too many minerals in it. So, installing a water softener will no longer require it so hard and you’ll see its effect on your energy bills. In the long run, installing a water softener is a cost-saving solution.

How Do You Know If You Have A Hard Water Supply?

Now, you know the benefits of using a water softener. But it’s only needed when you have a hard water supply. And if you can’t detect whether the level of hardness in your water supply is hard or not, you won’t be able to make a decision on that.

One common sign of having hard water is that you’ll hear noises coming from your water heater. It’ll mostly be a banging noise like when popcorn is popped. It usually comes from the heat exchanger as the minerals settled on it begin to expand due to the heat.

But it’s not just your water heater that’ll tell you when you have a hard water supply. Many other signs can help you spot this issue.

Your skin and hair will feel brittle, the dishes will have streaks, and the floor and curtains of your bathroom will get dirty sooner. Those are some of the signs of knowing that you surely have a hard water supply in your home.

Should I Follow Any Water Softener Maintenance Checklist?

Yes, water softeners also need checking and maintenance for optimal performance. Even though they can last for years without any supervision, taking good care of them will help them last longer. Here are some water heater maintenance tips for you:

i) Maintain The Brine Tank

You need to check the salt levels in your water softener at least once a month. It should have a clear guideline on when you should replenish the salt. Usually, filling half of the tank with salt and keeping it a few inches above the water level is good.

There are many types of salt such as granular, tablet, or block salt. You should use the right type of salt for your system. If you’re unsure about the right salt type, you can ask an expert or check the manual.

Sometimes, salts can form a solid layer of a bridge and interrupt the loose salt from mixing with the water below. You can push the handle of a broom to break those areas. You can pour hard water on them as well to make the process a little easier.

Keep in mind that mush can also form at the bottom of the tank. You can also break it using the broom technique. The brine tank should be free so that the salt can mix with the water and break down the minerals.

ii) Clean The Tank

Water softeners made these days are tough and can go without a cleanup for many years. But you may have to clean them if the water has turned hard and you can’t clear the tank with regular maintenance.

The first step to cleaning the tank is to empty the tank. Turn off the bypass valve and discard the water and salt in the tank. Then, remove the brine grid at the bottom of the tank. If your unit has any mesh platform, you can just set that aside and continue the process.

Then, you need to clean them. Dish soap would be fine for this job. Pour a decent amount of dish soap into one or two gallons of water. Dump that mixture into the tank and scrub the interior of the tank with a brush.

After you’re done cleaning it, rinse the tank with water. You can also use bleach to do a final cleanup. Add 50-60 ml of bleach and 1-2 gallons of water to the tank. Let it sit for a while and the tank will be completely sanitized.

Then, you can restore the tank to its original state. Refill the water and salt content in the tank. Wait for a few hours before you start using the water softener again.

iii) Additional Water Softener Maintenance

If the brine tank gets clogged, cleaning the valve between the brine and the resin tank is a great idea. You should do it once or twice a year to maintain the health of the water softener. Make sure you relieve the water pressure before you take the parts apart.

Follow the instructions in your owner’s manual for detailed guidelines on how to do it. If you still have a hard water issue even after adhering to the above maintenance tips, you can do these things:

  1. If there are any problems with the water pressure, make sure to fix them.
  2. Make sure the hoses are not bent or have any kinks, and the regeneration timer is active.
  3. Check if the electrical connections are secure and the unit has power.
  4. Set the timer so that it regenerates more often if the use of water in your house has increased.
  5. If nothing works, contact a professional plumber to assist you.


Does an unclean air intake filter lead to an error code in a Navien tankless water heater?

A clogged air intake filter often leads to the E109 and E110 error codes. Clean the air intake filter to remove these codes so that you can continue using your water heater.

How often should you clean the air intake filter?

You should clean the air filter before it gets clogged up but not so often that it becomes a nuisance. I think you’ll be safe if you clean it every 3-4 months. However, it can vary depending on how fast the air intake filter gets dirty.

Why does no hot water come on when you open a hot water faucet?

The main reasons why you may not get hot water are a dirty water inlet filter or the water heater being frozen. Apart from that, there could also be an error code signaling why the water heater hasn’t come on.

How much do Navien tankless water heaters cost on average?

The price of the Navien tankless water heaters depends on many factors like their size and models. But the price of the residential models is normally around $1200 – $2500.


Now you know all about the Navien tankless water heater maintenance practices that you need to follow. If you do them in the right intervals, you can surely expect your water heater for a long time. Hopefully, you’ll find all the maintenance tips easy to follow and practice them.

The most important one is to flush your heat exchanger. If you don’t do that, it can get damaged. If it’s already too late and the damage is done, I have a guide on fixing the Navien tankless water heater heat exchanger failure. Check it out to learn more about it.

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