How To Descale A Tankless Water Heater

Descaling your tankless water heater is essential to keep it running smoothly and efficiently. Without proper maintenance, the water from your tap could be filled with scale and other minerals, leading to costly repairs in the future.

But don’t worry – descaling your tankless water heater is a relatively simple process that can be done in an hour or less.

In this article, we’ll explain why descaling is important, how often you should do it, and what equipment you need, and provide a step-by-step guide on how to descale your tankless water heater. So grab some vinegar and let’s get started!

How To Descale A Tankless Water Heater

Why Do Tankless Water Heaters Need to Be Descaled?

Descaling a tankless water heater is essential to its proper functioning and longevity. Scale, or mineral deposits, can quickly build up in the heat exchanger, submersible pump, and other components over time.

If left untreated, limescale buildup can cause your heat pump to work harder and reduce water flow, eventually resulting in a need for a replacement of your tankless water heater!

How Often Should You Descale a Water Heater?

Generally, a tankless water heater should have its first descaling treatment three years after installation. If sediment is discovered during the descaling flush, another should be performed in three years; if no sediment is discovered after the initial flush, further descaling may not be needed for five years.

If you have hard water in your area, it is recommended that you flush your water heater more often than the suggested schedule.

To determine the best descaling schedule for your specific circumstances and location, consult with a trusted plumbing professional or check with your city government about local water quality levels.

How Do I Know If I Need to Descale a Tankless Water Heater?

If you’re not sure whether it’s time to descale your tankless water heater, the first step is to check the USGS website for a map of your area that indicates the levels of hardness in the water. If you live in an area that is marked white or red, then it’s likely that your tankless water heater will need regular descaling. It is not necessary to flush blue areas as part of routine maintenance, but if desired a flush can be done every two years.

Modern tankless water heaters are equipped with sensors and apps that can detect when it’s time for maintenance. Smart tankless appliances can run their own diagnostics and will notify the owner when maintenance is required – negating the need for manual checks.

How to Descale Your Tankless Water Heater

Descaling your tankless water heater is an important part of its maintenance. Without regular descaling, your water heater can become clogged with minerals and debris, leading to decreased efficiency and dangerous error codes.

If you have a tankless water heater, it’s time to descale it! Professional help is recommended when performing this task, as tankless heaters are often installed in the walls of the home and can be difficult to disconnect and reconnect properly.

To begin, first obtain a descaling solution specifically made for tankless water heaters, as well as a bucket ready to collect any excess water. Descaling your tankless water heater will ensure it continues working efficiently for years to come!

Required Equipment

Descaling a tankless water heater is an important part of maintaining it. The process involves flushing out the scale and other deposits that can build up in the system. To begin, you will need to gather some necessary equipment. First, make sure you have a bucket of fresh water, a 1-quart bottle of Flow-aide descaling solution, and a hot water drain hose.

Step by step guide

Descaling a tankless water heater is not as difficult as it seems. With the right tools and a little patience, you can have your heater running like new in no time. Here’s a step-by-step guide to descaling your tankless water heater:

Turn Off The Heater

It’s essential to turn off the heater before attempting to descale a tankless water heater. If you have a gas tankless water heater, simply turn the gas valves counterclockwise and you’re done. However, electric tankless water heaters require a little more effort. Ready to take the chill out of your home? All it takes is a quick trip to the breaker panel and flip the switch for your heater.

To ensure your safety, it’s also important to turn off the heater itself. This may require some disassembly of the unit but don’t worry – this can easily be done on your own. Taking these steps is essential in ensuring that no further damage occurs during the descaling process and that all safety precautions are taken.

Turn Off The Water Supply Valves

Descaling a tankless water heater doesn’t have to be complicated! All you have to do is shut off the water supply valves – they’re normally underneath the heater and just require you to give them a tiny funny-bone rotation movement, counterclockwise. Don’t forget to find the service or draining valve, which you’ll need later.

Afterward, get an empty bucket and place it under the heater for when you drain it. Then, connect hoses from the A and B valves of the isolation ports to drain any remaining water inside—about one liter should come out of it. Once that’s done, be sure to flush out any excess water with fresh drinking water before turning on your tankless heater again.

Following these steps will ensure that your tankless heater is properly descaled and ready for use!

Connect The Hoses And Descaling Pump

Descaling your tankless water heater is an important part of the maintenance process. To ensure that your water heater runs optimally and efficiently, it’s essential to descale its internal components. The good news is that it doesn’t have to be a difficult or complicated task! All you need is a submersible pump, two hoses, a bucket, and some descaling solution.

Begin by connecting one end of one hose to the blue cold water valve and the other end to the submersible pump. Connect the second hose to the valve dripping with steaming hot water, and guide the free end into a container of crystal clear liquid.

Make sure both hoses are securely tightened with a wrench so no leaks occur. Once you’ve connected the hoses, plug in the pump and turn it on – you’re ready to start descaling!

The pump will draw in gallons of incoming water from the inlet valves while simultaneously pushing out liters of outgoing water through isolation valves. The descaling solution then circulates through your heat exchanger before being drained out through drain ports, leaving your electric tankless water heater sparkling clean!

Add Vinegar And Start The Process

Descaling a tankless water heater can seem like an intimidating task, but with the right steps and tools, it can be done quickly and safely. To begin the descaling process, start by locating the inlet water valve and outgoing water isolation valves.

When you’re ready to set up, make sure you have a bucket handy—that’s where the pump will live. Don’t forget to attach one end of the hose to your hot water valve too!Then pour four gallons of white vinegar over them. Now open both the hot and cold water drain valves as well as turn on the circulation pump.

Let the pump run for at least 30 minutes, or ideally an hour, then turn off the pump and let any excess water flow back into the bucket. Keep in mind that if you’re using an electric tankless water heater, make sure it’s unplugged during this process.

Once complete, you should no longer see any error codes related to descaling and you’ll have clean drinking water from your conventional or tankless heater!

Clean The Air Intake Filter

Cleaning the air intake filter on your tankless water heater is an important step when descaling. It is easy to overlook but needs to be done regularly in order to keep your heater operating efficiently and effectively.

Every model of tankless water heater is different so it’s important that you consult the user manual for your model in order to locate where the air intake filter is located and how you can access it.

Until the heater flushes out, you should have plenty of time to clean this filter as well which will help extend its life span and ensure that it continues to provide hot water without interruption. If left uncleaned, debris from the exhaust can clog up the heat exchanger, submersible pumps, the flow of water, and tank drain ports which could eventually result in a total malfunction of your electric tankless water heater.

Don’t wait until it’s too late – take a few minutes out of your day and give your air intake filter a thorough cleaning with fresh water or even a descaling solution if needed. Make sure you also have a bucket of water nearby just in case!

This small effort can make all the difference between having consistent hot water for many years or being forced to replace your conventional tankless water heater with a new one due to lack of maintenance.

Rinse The Water Heater

Rinsing the tankless water heater is an important part of descaling it. To begin, remove the hose attached to the cold water inlet valve and the circulation pump. Once you have done this, cap off the service valve and turn on the cold water.

Water will circulate through your unit and into a bucket, which should be prepared beforehand. Make sure to leave the hot water hose on throughout this process so that there is no interruption in the hot water supply.

After the bucket is full, turn off the cold water and allow any excess water to drain out of your system. This rinsing process will flush out all of the vinegar used during the descaling as well as any other deposits that may have built up over time. Rinsing your tankless heater every few months ensures clean drinking water and a longer lifespan for your conventional or electric tankless heater!

Turn Your Descaled Tankless Water Heater Back On

Once you’ve finished descaling your tankless water heater, it’s time to turn it back on.

Get the hose sorted and fasten those connections firmly – you don’t wanna be left with a leaky mess! Make sure that there are no leaks before turning on the power. The hot water should circulate as usual if you’ve followed each step correctly.

If you don’t experience any problems after turning your unit back on, then you completed the job successfully! But if something goes wrong or you suspect a problem, call an expert for assistance immediately. Descaling your tankless water heater is a great way to keep it running smoothly and efficiently – but only if done properly!

Flow Aide vs Vinegar

Vinegar is often regarded as the go-to solution for descaling a tankless water heater, but Flow Aide works much better. If you live in an area with hard water or haven’t flushed your tankless water heater in a few years, then it’s definitely worth upgrading to Flow Aide. It packs a punch when it comes to tackling limescale buildup and will be more effective than relying on vinegar alone.

For regular flushing of your tankless water heater once a year, vinegar can still provide good results. However, if there is an excessive buildup of limescale within your system, then opting for Flow Aide instead would be recommended. Not only does it work faster than vinegar, but it also keeps your tankless water heater running more efficiently so that you can keep up with all your hot water needs.

Ultimately, it’s important to note that choosing the right descaling solution plays an important role in properly maintaining and caring for your tankless water heater. So before you make any decisions on which solution is best for you, consider the amount of build-up present and ensure that you are making the most informed decision possible.


Why Choose a Professional for Tankless Water Heater Descaling?

A professional technician has the right experience and knowledge necessary for safely descaling your tankless water heater. They will be able to accurately assess the system and properly identify any problems that need attention before they can start the descaling process. Furthermore, they also have access to specialized tools and equipment that helps them efficiently finish the job without causing any damage or harm.

In addition, professionals are also aware of safety protocols such as shutting off gas lines prior to their service and checking for carbon monoxide levels after completion.

What happens if you don’t flush your tankless water heater?

If you don’t flush your tankless water heater, you’re putting yourself and your home at risk. Over time, scale build-up will erode your tankless water heater and cause big problems. Even a thin layer of scale will increase your energy costs by up to 30%.

Does your water heater struggle to keep up with hot water demands? Don’t let it become a bottleneck and reduce its lifespan! If not serviced regularly, it can cause costly repairs or even worse, lead to complete failure of the unit. Descaling must be done every 6 months or so to prevent scale build-up from damaging the components of the unit.

How to avoid the need to descale a tankless water heater?

Dealers work by emitting electrical pulses through coils wrapped around the main pipe, creating a capacitive effect that alters mineral crystals in hard water so they dissolve before causing any damage. As an added bonus, this process doesn’t add any sodium or other chemicals to your water supply.

With a descaler installed on your tankless water heater, you won’t have to worry about regular descaling or costly repairs due to limescale buildup. It’s an easy and cost-effective way of protecting your investment and ensuring that you have hot water whenever you need it.


Descaling a tankless water heater is an important part of maintaining your system and ensuring it runs efficiently. It helps remove deposits that can form on the inside of the unit, reducing its performance and potentially leading to costly repairs. Fortunately, it’s a fairly simple process that anyone with basic DIY skills can do themselves.

All you need is a descaling solution and some patience. Start by turning off the power to the heater and shutting off any water valves connected to it. Next, flush out the unit with some fresh water until all of the old water has been drained out. Then mix up your descaling solution according to the instructions on the bottle and pour it into the inlet pipe of your heater.

Leave it for a few hours before flushing it out with fresh water again until all traces of the descaler are gone. Finally, turn back on both power and water supplies, and you’re done! Descaling your tankless water heater regularly will help extend its life and keep it running at peak efficiency for many years to come.