How To Descale Rinnai Tankless Water Heater? 3 Common Phases!

How to descale Rinnai tankless water heater? You can descale a water heater with only 3 phases; the preparation stage, flushing, and the cleaning-up stage. With these phases mentioned, you can quickly and systematically descale your water heater.

Like cars and other appliances we use in everyday life, water heaters also need maintenance. Maintenance helps prevent the damage build-up that accumulates inside the unit over time.

How to descale Rinnai tankless water heater

So, if you have a Rinnai Tankless water heater system, you might want to arrange to get it checked once in a while. But how will you do it? Stay tuned and read` up til the end of this article to find out how!


Rinnai Tankless Water Heater

One of the advantages of a tankless heater is it incurs minor corrosion since no tank collects the water. These are proven to be more durable than the traditional water heating systems that come with tanks since you will have to take care of both the tank and the heater itself.

Since there is a lower risk of corrosion, it doesn’t mean that it will not get damaged over time. It will. The minerals in the water will still build up as time passes and eventually erode the walls of the heating chamber. So to take care of your tankless heater, you must clean it and remove the mineral deposits that sit inside from time to time. 


Phases To Descale Rinnai Tankless Water Heater

So, how to descale Rinnai tankless water heater? When descaling or flushing your Rinnai tankless water heater, you must go through three phases. These phases will help in systematically finishing the whole cleaning process. You’ll have to follow the simple steps in each stage so you will have an easy time cleaning your tankless heater.


Phase #1. Preparation

The First Phase of the cleaning process is Preparation. As in every task, safety first. Disconnect all electrical sources. That includes the power source plug that connects to the electrical outlet. Before removing the access panel, use a non-contact voltage tester to ensure no more extended power. A Rinnai unit has three water valves, one is for the cold water, and the other is for the hot water, while the third is for the release valve connected to your main household valve. Then find the gas isolation valve and the hot and cold shut-off valves and close them. Next is to locate the hot water pressure relief valve and open it to release any pressure build-up inside. Be careful with handling since it may be too hot when releasing pressure.

There is a cold and hot water service port in the heater. Connect both of these ports to their respective hoses. Connect the cold hose to a submersible pump placed in a bucket, the hot water hose into the bucket itself. Add four gallons of undiluted virgin white vinegar into the bucket. If you don’t have that much white vinegar with you, I suggest having a gallon of CLR and 3 gallons of water as an alternative. You might want to check out the users-manual again for the flushing and draining process to ensure the steps. There are various Rinnai tankless water heater models and types, so the flushing and draining procedures may differ. The cleaning usually lasts for 45 minutes at most. 


Phase #2. Flushing

The next phase includes the soaking and draining of the solution. After adding the solution to the bucket, turn the pump ON. Let the solution circulate through the heater for at least an hour as it dilutes the mineral build-up that sits in the heater chamber. After an hour, turn the pump off and dump the solution off. Remove the attached hoses and close the cold water port.

Open the cold water shut off and flushes out the sediments and the remains of the solution. The process will take up at least 10 minutes to finish. After flushing the solution off, close the valve and use water to drain the second hose. Once the water has finished draining, near the hot water service port, remove both the cold and hot water inlet filter and wash it off on a sink to get the sediments left of the draining. You may also want to read about flushing a tankless water heater.


Phase #3. Cleaning and finishing

The last Phase includes the finishing clean-up of the water heater to get it ready for subsequent use. After cleaning the sediments off the filters, place them back to their respective shut-off valves. Re-attach the access panels and try opening the shut-off valve. Try reconnecting the electrical power supply to the outlet and see if the heater works well. Check the users-manual once more to see the instructions on restarting the unit. You need to rotate and open both cold and hot water valves in most cases. These valves are parallel to the main valve’s location.


It’s A Wrap!

Knowing how to descale Rinnai tankless water heater will not only save you some bucks for the labor cost, but you also learned how to maintain your water heater. These tankless water heaters may serve you in the long run, so it is best to know how to prevent them from accumulating damage over time and knowing how to maintain them clean. Click on these links to read related articles; know how to clean tankless water heater and how much is a tankless water heater. I hope you learn something from this article, until next time!

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