Maintenance Tips for your Tankless Water Heater

January 29th 2021

Tankless water heaters are an attractive option for heating your home’s water. With benefits including savings over time, great energy efficiency, and significantly smaller storage space, Valleyshore Plumbing is excited to help their BC Lower Mainland clients convert from a traditional storage water heater.


This upgrade to new technology doesn’t mean that maintenance needs disappear, but you may find that most of the maintenance needed can be completed yourself. In this article, we’ll look at a few tips for maintaining your tankless water heater.


Things to Do Before Tankless Water Heater Maintenance


Before performing most types of maintenance on the unit, there are a few steps to take to get ready. Do not perform any maintenance until you have reviewed these items and completed any that are necessary for the maintenance you will do:


-Unplug the heater’s electric power cord. Additionally, you might turn the unit off from your circuit breaker, to be even safer.


-Turn OFF the manual gas valve to stop the gas supply to the heater.


-Turn off the water supply to the unit. Most units have an isolation valve installed so that you can isolate the unit instead of shutting off all the water in your home.


-Make sure the water inside the unit has cooled down enough that it doesn’t burn you.


What to Check – and Some Tips


There are a few parts of the tankless water heater that need to be checked. Here are a few tips for checking them!


Pressure Relief Valve

This valve allows you to release water pressure from the unit if it goes above the allowed limit. You may never need to use it, but if you ever do it must work! Once per year, test the valve by lifting and releasing the lever. If it’s working properly, it should quickly return to a closed position and seal.


Be careful that the internal water isn’t scalding hot when you test this valve!


Combustion Chamber

Once a year, it can be helpful to use compressed air and a dry cloth to remove any dust, debris, and dirt from the combustion chamber. Like cleaning out a computer, a can of compressed air from the electronics department of any local store will do if you don’t have access to an air compressor.



The vents on your heater make sure that heat and gases from the water heating process are vented out properly. Make sure there are no obstructions to the vents and check that all gaskets are in good condition.


Water Filter and Sensor

Remove any mineral deposits from the water filter and sensor. The unit’s flow sensor should be able to spin freely. If it doesn’t turn properly, try using lemon juice to clean it. If that doesn’t work, you’ll probably need to replace it.



With a small piece of fine-grit sandpaper, you can clean the tip of this ignition rod to a bright finish. If you do this, make sure that any flame sensors stay in their factory positions.


Sediment and Limescale Build-up

Most heaters are equipped with a diagnostic tool that informs the owner when flushing the tank is needed. Flushing helps remove sediment and limescale deposits. If you don’t receive those alerts, or if they don’t seem to come often, we recommend flushing your unit at least once per year.


When flushing your unit, you can use manufacturer instructions (if those are included and accessible) or you can use a process online like this one at WikiHow about How to Maintain a Tankless Water Heater. You can also buy tankless water heater maintenance kits from stores like Home Depot.


We hope these maintenance tips help! A properly maintained tankless water heater should last you around 20 years, so we want to help you keep it running well for all those years!


If you find you’re in over your head or don’t have time to maintain your unit, contact us at Valleyshore Plumbing in Langley to provide regular maintenance. Our Red Seal certified plumber has been in the industry for over a decade and can quickly and easily make sure your tankless water heater is working as it should.


For more plumbing tips about renovations, maintenance of plumbing in your home, or even an article about why you should upgrade to hot water on demand, check out our Plumbing Tips page!

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