Flushing your water heater: everything you need to know and more

If properly maintained, your water heater should last about 10 years. But how exactly do you maintain your water heater?

Is it possible to clean the inside of your water tank? If so, how often should you clean it? The answers to these questions depend on many factors, but especially on the type of water heater you own.

You don’t need to drain your electric water heater if your water supply comes from a municipal water system and the quality of your water is good. New electric models do not require flushing, and there is no indication that draining your appliance will extend its lifespan. Some specialists go so far as to say that flushing your water heater could increase the proliferation of bacteria or cause rust to appear in the tank!

However, if your water heater is connected to a water well and the water is hard, contains iron or is rich in calcium because of where you live, regular flushing is recommended.

Why drain your water heater?

Sulphur, iron, scale and other deposits can damage the water heater’s inner walls and water pipes. In addition to diminishing the quality of the water, these deposits can hinder the efficiency of your appliance.

How to drain a water heater in 10 steps:

Before you begin flushing your electric water heater, make sure that it is necessary! As mentioned above, draining an electric water heater is rarely needed and only required in specific situations. If you have any doubts about the necessity or the safety of the procedure, be sure to call a professional.

If you wish to drain your water heater yourself, try to use as much hot water as possible (bath, shower, dishes, etc.) before flushing your water heater. That way, the tank will be partially emptied.

Then proceed with the steps below while always keeping safety in mind:

1. Turn off the water heater’s power supply. Switch the circuit breaker to “OFF”.
2. Shut off the cold water supply valve (at the top of the appliance).
3. Turn on a hot water tap somewhere in your home to let air into the tank. This will also allow you to test the water once you turn on the water heater again at the end of the procedure.
4. If there is no floor drain at the base of your water heater, connect a garden hose to the drain valve (at the bottom of the tank). Direct the end of the hose to a floor drain, bathtub, shower or outside.
5. Slowly turn on the drain valve to avoid scalding, then let the tank empty itself completely.
6. Turn on the cold water supply valve and keep the water running at full pressure for several minutes. Make sure that you completely flush out any sediments from the tank.
7. Turn off the drain valve once the water runs completely clear.
8. Let your water tank fill up. You’ll know when your water tank is full when the hot water tap, which you turned on earlier, runs normally without any residual air coming out.
9. Turn off the tap.
10. Turn the water heater’s power back on.

When should you drain a water heater and how often?

If your situation calls for regular flushing, it’s important to do so from the installation. The procedure may be recommended every 1 to 3 years, depending on the quality of your water.

If you decide to drain your water heater after a few years without previous maintenance, you could do more harm than good. As the strongly encrusted sediments loosen, the inner tank will become weak and corrosive, which might make your water heater rust prematurely.

As for propane and natural gas water heaters, they require flushing once a year. Since the procedure is more complex than with electric water heaters, we suggest you call a qualified technician.