What maintenance is required for a tankless water heater

Tankless water heaters are a feature of many Calgary homes, but do you clean and flush yours every year? If not, it’s time to start!

The maintenance a tankless water heater requires can be simple, but it’s not something you want to put off if you enjoy clean water.

Here’s everything you need to know to care for and maintain your tankless water heater.

The maintenance required by a tankless water heater

1) Turn it off

Just like any device, turn your tankless water heater off before performing any maintenance. You can do this by turning off the main gas – or the circuit breaker if your heater is electrical.

2) Stop the water flow

You don’t want water flowing while you’re maintaining your tankless water heater, so ensure you turn off each of the three water valves attached to your heater:

1. Cold water valve – may be coloured blue.
2. Hot water valve – may be coloured red.
3. Main water valve – this might not be coloured.

3) Prepare for purge

Next up is purging any pressure that has built up inside the valves in the system.

Carefully remove the purge port valve caps from the purge valves; these can be found on the cold and hot water valves—they have small, often T-shaped handles. Be sure the rubber washer sealing discs stay inside as they’re vital for valve function.

Before you start, make sure you have turned off the hot water valve completely as any pressure build up may cause the water to shoot out. If that meets your skin, it’s going to burn.

You’ll also want to be extremely careful – and probably wait a while to carry out maintenance – if you used the hot water immediately before carrying out this procedure.

4) Attach hosing lines and purge

Your tankless water heater should have come with hosing lines. If not, you may need to purchase some.

Attach the hosing lines to each of the valves. Some models may require a sump pump to make this work, so be sure to check the manufacturer’s instruction manual for you water heater.

Open the purge port valves with a 90-degree twist.

5) Flush and drain

Now it’s time to get the manufacturer’s instruction manual out. Follow their flushing and draining procedure. This can take around 45 minutes or so.

Some manufacturers suggest using chemical cleaners. But remember – this is your family’s drinking water. Using around 2.5 gallons (9.46 litres) of undiluted white vinegar is a safer solution.

If you have hard water and are wondering if the vinegar is going to be effective, perform the procedure twice for an hour each on consecutive days.

6) Close up, reconnect, replace, restart

You’re nearly there! Once the flushing process is complete, close the purge port valves with a 90-degree twist in the opposite direction.

Disconnect the hose lines and replace the purge port valve caps. Make sure these are tightly sealed and the rubber washer sealing discs are still in place.

Check your instruction manual once again to confirm how to restart your tankless water heater.

7) Final run

Now it’s time to bring your water system back to full function. Slowly turn on the hot water tap at your sink. This allows the air to pass through the pipe.

Keep the tap on until the water runs without air interruptions. This shouldn’t take more than three minutes or so.

You’ve now provided the necessary maintenance your tankless water heater needs. Make sure to mark your calendar for next year’s maintenance check!

Don’t like the idea of handling this whole process yourself?

Not a problem. Son-Rise Plumbing and Gasfitting has been providing Calgary with experienced and dependable professional plumbers since 1983.

Reach out for assistance with maintaining your tankless water heater.

Contact us!