How to drain a hot water tank
One of the most overlooked chores homeowners should do regularly is drain a hot water tank. Easy to pass by, your water tank accumulates mineral deposits and filth over time. By draining your hot water tank, it allows for it to run more efficiently and prolong its shelf life.
Below we have documented the hows and whys into draining a hot water tank. As usual, your local Toronto plumber will be able to give you the best in hot water tank care.
How often should I drain my hot water tank?
Our recommendation is that you should drain it at least once every three years to be safe. If you have the time, aim to do it once a year.
How to flush a hot water tank?
There are two different types of hot water heaters: gas and electric. Let’s dive into gas water heaters as its only major difference maintenance-wise is to shut off the gas before draining.
- Turn off your water heater’s thermostat
Usually, the thermostat is found near the bottom of the tank. Some have the opinion to just turn your heater to “Pilot”. To be safe, set it to “Off” before doing anything. If you have an electric water heater, turn off the circuit in the breaker box.
- Turn off the gas to the hot water tank
If your heater is gas-run, you will want to turn the gas valve to the “off” position.
- Turn the cold water supply off
Towards the top of the tank, turn the cold water valve off.
- Turn the hot water on in a sink or tub
During the flushing process, leave either a sink or a tub running with hot water. By doing this, it will make sure a vacuum doesn’t start forming in the lines while you’re draining the tank.
- Pressure Relief Valve – Open it
To allow for the water to flow more easily during the draining process, we recommend opening the pressure relief valve. This will also allow you to test your pressure. Make sure to place a bucket underneath the drain pipe on the pressure relief valve before opening the water as it will rush out. Note, the water will be hot! If water does not come out, it might be faulty and would require a more seasoned plumber to replace it. After allowing the water to be released, wait for the water in the tank to cool.
- Ensure the water is flowing outside
Before turning on the spigot, be sure the end of the hose is heading outside or into a bucket. If your hot water tank is in the basement, you might need an external pump to drain to the main floor.
- Drain the tank by turning on the spigot
Drain the tank until the water has no more deposit in it. If you see a lot of build-up and sediment, you might need to drain it completely.
- Flush the water out
Turn on the cold water spigot leading to the hot water tank and flush your hot water tank. Run it for a few minutes until the hose runs clear water. Then turn off the cold water spigot.
Finishing the draining process
Once you’ve completed the above process, ensure you put things back to the way they once were.
- Turn off the draining spout and take out the hose.
- Close the pressure valve if you’ve opened it.
- Turn off the water to the tub or sink that you turned on when you started.
- Turn on the cold water spigot leading into the hot water tank.
- When your tank is full, open the relief valve to let out surplus air.
- Turn on the hot water spout of any sink or tub to get the air out of the system. Cold water should be coming out – turn it off now.
- If you shut the gas off, turn it back on now.
- If you turned off the thermostat, turn that back on by re-lighting the pilot light.
- If your water tank is electric, flip the switch back on in your circuit breaker box.
- Wait 15-20 minutes for the water to heat up. Turn on the hot water spout in your home somewhere to make sure it’s all in working order.
Be sure to check with your local plumber to make sure you took all the proper steps in draining your hot water tank!