When was the last time you flushed the hot water heater in your home? It’s important that this be done at least once a year to remove sediment that accumulates on the bottom of the tank. That's especially true if you live in a hard-water area or run off a private water well. Sediment buildup reduces the heating efficiency of your water heater costing you money in the long run.
One sign of excessive sediment buildup is a popping or rumbling sound coming from your water heater. That's the sound of steam bubbles percolating up through the muck. On a gas water heater, the sediment creates hot spots that can damage the tank and cause premature failure. On an electric water heater, sediment buildup can cause the lower heating element to fail. Flushing offers a payback in lower energy bills and extended heater life.
First turn off your water heater. There are two types of water heater, gas and electric. If you have a gas water heater then you can turn it off by shutting off the gas supply at the main valve to your heater. If you have an older model gas water heater remember that you may need to relight your pilot light once you are finished. If you have an electric hot water heater simply turn it off the breaker at your homes main electric panel or breaker box. Make sure you are turning off the correct breaker. Your water heater must be off for this procedure.
Next turn off the cold water supply to your water heater. This can usually be found at the top of your water heater.
Next turn on the hot water in either a sink or tub in your house. Leave this on for the entire process to prevent a vacuum from forming in your lines.
Next open the pressure relief valve. This isn’t a necessary step, but it can help water flow more easily while draining and it allows you to test your pressure relief valve, thus killing two birds with one stone. Make sure you have a bucket beneath the drainage pipe on your pressure relief valve before opening as water will be rush out. Be careful. This water will likely be very hot. If water doesn’t come out, you’ve got a faulty pressure relief valve and it will need replacing.
After you’ve opened the pressure relief valve, let the water in your hot water tank cool.
Then connect a garden hose to the spigot at the bottom of your water heater. Make sure the other end of the hose goes outside, into a drain, or at least in to a bucket.
Turn on the spigot and drain your water heater until the water runs clear. Then flush the system by turning on the cold water inlet valve that you previously turned off.
Once the water is clear you are done.
To put your water heater back into operation.
Turn off the drainage spigot and disconnect hose.
Close the pressure relief valve if you opened it.
Turn off the water on your sink or tub that you turned on at the beginning.
Turn on the cold water spigot leading to your hot water heater.
When the tank is full, open the pressure relief valve to let off any excess air.
Turn on the hot water spigot of a sink or tub to get the air out of the system. Cold water should be coming out of the faucet at this point. Turn it off.
If you shut off the gas to your hot water heater, turn it back on.
If you turned the thermostat off on your hot water heater, re-light the pilot light (it’s easy follow the instructions on your hot water heater), and then turn it to on.
If you have an electric hot water heater, flip the breaker switch on your electrical panel that gives power to your hot water heater.
Wait about 20 minutes for the water to heat up. Turn on a hot water spigot somewhere in your house to ensure hot water is coming out.