How To Flush A Tankless Water Heater? Gas; Electric 2020

How To Flush A Tankless Water Heater

Nothing is more annoying than taking a bath with cold water on a winter morning. As a matter of fact, no one can even imagine that. Tankless water heaters, also known as instantaneous water heaters, provide hot water on demand. They are compact in size so you can install them in a closet, exterior wall, or any other convenient place. Tankless water heaters are energy-efficient and save you money on energy bills every month.

Tankless water heaters heat water on demand instead of storing it in a tank. Over time tankless water heaters accumulate minerals that can erode the walls inside the heating chamber. Manufacturers of tankless water heaters recommend flushing the unit at least once a year to eliminate the buildup of minerals in the unit. Failure to flush the tankless water heater results in pointless fuel expenses. It can also reduce the service life of the unit as well.

Flush A Water Heater 2020

Why descaling Tankless water heater is necessary?

A tankless water heater is better than a tank water heater in many aspects. But both can be affected by the buildup of minerals. When it comes to doing the house chores flushing the tankless water heater can be overlooked. But you need to understand that flushing a tankless water heater is an important task if you want the unit to keep performing at its optimal level. If you do not flush your tankless water heater, then the unit may get damaged, and the cost of repair can be annoying. That is why the manufacturers recommend flushing a tankless water heater every twelve months.

You invest your hard-earned money to ensure that you get hot water when needed, so take care of the hot water tank maintenance.

How to flush a tankless water heater?

Do you know how to flush a water heater? Flushing water heater is essential, and you should do the job at least once a year.

Flushing an electric tankless water heater:

An electric tankless water heater requires less maintenance than a gas tankless water heater. No matter what type of heating unit you have installed water flushing is needed. Most manufacturers recommend annual flushing, but the flushing frequency should be determined by the hardness of the water. If the water is getting harder, you need to do the flushing more.

Now let’s discuss how to flush the water heater. Here is the process of flushing an electric tankless water heater:

Turn off the electrical power unit. To prevent water from entering the unit, close the Cold Water Shut-off Valve. Open the faucets to drain the water from the unit. Remove the cover and check that no electricity is reaching the unit. Make sure that you double-check it. You can use a non-contact voltage test for this purpose. Then remove the screws. loose the hexagon brass top. You can use a wrench for this purpose. To remove the heating element, rotate anti-clockwise. Then place the heating elements inside the cooper chambers. Don’t forget to inspect the heating elements. If they need to be replaced, then do it.

The use of vinegar:

  • Now fill the chambers with virgin, food-grade white vinegar.
  • Allow it to soak in the chamber for 9-120 minutes
  • Drain the vinegar
  • Then replace the heating elements
  • Then secure the wires using a screwdriver

Now it is time to remove the vinegar from the unit. Open the cold water shut off valve. Fill the tank with water and then open the hot water shut off the wall. Don’t forget to check leaks. Then open the water faucets so that the water can flush out the vinegar.

Flushing a gas tankless water heater:

Here is the process of flushing a gas tankless water heater:

First of all, disconnect the electric power to the unit. Remove the access panel and then check that all the power has been disconnected. You can use a non-contact voltage tester to confirm it. After that, you have to close the hot and cold water shut off valves. Then open the hot water pressure relief valve. It will relieve the pressure, but be careful that the water released may be very warm.

Then connect the end of one hose to the cold water service port. Connect the other end of the hose to the Submersible Pump. Then place it into a five-gallon bucket. Then you have to connect the one end of hose number two to the hot water service port and the unattached end of hose number 2 to the bucket.

Then fill the five-gallon bucket with four gallons of white vinegar (virgin, food grade). Remember not to dilute the vinegar. Then open the cold and hot service ports. Turn ON the Submersible Pump and let the vinegar circulate for at least sixty minutes. If the pump is circulating at a lower rate, then allow it to run longer as it should run at a rate of four gallons per minute. Now turn the Submersible Pump ‘OFF.’

Flush the vinegar:

Now it is the time to rinse/flush off the vinegar.

Remove the unattached end of hose number 2 from the bucket and place it in a drain. Then remove the hose number 1. Close the cold water service port and open the cold water shut off valve. It will flush out the vinegar from the unit. Allow the water to run off for at least ten minutes. Close the water shut off valve to stop water from flowing through the unit. When the water stops draining, remove the hose number 2. Then close the hot water service port.


Never start the flushing process until you turn off the power and gas. Open the unit and use a tester to verify that the power is off. If you do not turn the power off and start flushing procedure, the unit may get damaged.

Why Are Tankless heaters gaining popularity?

Tankless water heaters are gaining popularity for good reasons. They have taken the place of conventional water heaters, and now people do not install bulky tank water heaters in their homes as they not only occupy enough space but also increase energy bills. Let’s take a quick at some of the reasons for the popularity of tankless water heaters:

  • Instant hot water:

In homes, you need an instant supply of hot water to take a shower, do the dishes and laundry, etc. A tankless water heater provides an instantaneous supply of hot water on demand. When you install it in the homes, you do not wait too long in the shower.

  • Low energy consumption:

A tankless water heater consumes less energy as compared to traditional water heaters. It reduces the amount you pay as energy bills every month. It happens because the unit provides water instantly, and the machine runs for a short time. Though the installation cost of these units may be high, it is still worth installing these units.

  • Less space:

One of the biggest advantages of tankless water heaters is that they take less space than conventional water heaters. People who live in small homes cannot install tank water heaters as they occupy enough space. A tankless water heater is a perfect option for them as it provides not only hot water on demand but is also compact in size.

  • Clean water:

Do you know a tankless water heater provides clean water than a tank water heater? Sediment accumulates in a tank water heater. Also, the storage tanks rust with the passage of time that contaminates the water. A tankless water heater provides water free of these sediments.

  • Longer lifespan:

A tankless water heater has a longer lifespan than a conventional water heater. Normally, these units last up to ten years. Buying a water heater is an investment that you don’t make again and again. So make sure that you purchase a unit that has a larger service life.


A tankless water heater is one of the essential appliances in the homes these days. These units are Eco-friendly and consume less energy. You can install them anywhere you want to. They don’t take much space and supply hot water instantly. With all these benefits, it would be a great move if you replace a traditional water heater with a tankless water heater. The initial cost is a bit high, but they save you money on energy bills every month.

If you want to save space or your water heater has a lifespan of more than ten years, then it is time to change the water heater. Your water heater makes noise; it means you need to install a tankless water heater. There are different companies manufacturing tankless water heaters. You can read the reviews before deciding what type of water heater you should install.

No matter you install gas, electrical, or propane tankless water heater, make sure it fits your budget and fulfills your hot water requirements. Never purchase a unit until you know its pros and cons too. You should collect information about the brand reputation before buying a unit. Then it will become easy for you to decide.

Also Dont Forget to Read Complete Review About Best Under Sink Tankless Water Heaters 2020. For Latest information check our Blog Section.

About the Author: Marcus Griffin

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