Flushing Your Hot Water Heater

Happy Belated Thanksgiving!

We spent a wonderful day with family. Turkey, stuffing, mashed potatoes and football. I love being reminded to grateful for everything I have in my life.

Last time, I posted my 'Winter Check List'. This week, let’s look closer at Flushing Your Hot Water Heater. As I mentioned last time, this appliance is often ignored until something goes wrong. The way a HW Heater works is simple. Cold water enters the tank and is heated and then exits the tank. The incoming water contains sediment, which is simply any solid material that isn’t dissolved in the water. Sediment can be sand or other grit. This sediment (depending on the size) will settle to the bottom of the tank or come out the faucet.

Anyway, small accumulations of sediment are not a serious problem. However, through neglect the depth of the sediment can start: 1) to interfere with the function of the drain valve, 2) increase the amount of dissolved minerals in the hot water, and 3) even affect the efficiency of the heating element(s) if it's allowed to accumulate.

So here are the steps to Flushing Your HW Heater

1) Shut off the Hot Water Heater

Electric: You need to turn the electricity off to the HW Heater. This is very important! Because if the electric heating element turns on and it isn’t immersed in water, it will burn out, this will lead to having to have it replaced or to the replacement of the entire HW Heater.

Gas: You need turn the temperature control to OFF or Pilot. Then close the shutoff valve on the gas line.

CAUTION: Do not proceed any further if you do not know how to relight the gas pilot! We strongly suggest you have a gas professional visit your home ONCE to instruct you on the proper procedure for relighting your pilot. Not only is this valuable information for you to have for tank flushing, but at any time that the pilot may mysteriously extinguish.

2) Turn off the Cold water supply to the tank. If you’re not sure which valve is the Cold, then feel the water pipes past the shutoff valves. The one that is warm or insulated is the Hot water pipe.

3) Attach a garden hose to the drain spigot / faucet. Then run the hose to
convenient drain location. A floor drain or sump pump hole is ideal for this, or you have the hose outside to a spot away from the house. (Note: The hose needs to be of good quality. A rubber hose is preferable over a vinyl hose, since vinyl can become very soft when hot water runs through it, which increases the risk of getting burned.)

4) Open up the Hot water side of any faucet (This relieves the pressure inside the HW tank.). Then open the valve on the tank’s drain faucet and allow the tank to empty.

5) When the tank is empty, turn off the drain valve and turn on the cold water. The force of the cold water entering the tank will loosen more sediment from the bottom of the tank. After the tank partially fills (5 – 10 minutes), drain the tank again.

6) If at any point turning Step 4 or 5, the drain valve becomes clogged, turn on the cold water supply to the tank and allow the water pressure to ‘blast’ the clog clear.

7) If you are still getting large amounts of sediment, then repeat Step 5 until the water coming from the tank is running clear.

8) If the drain water is running clear, you’re done Flushing the HW tank. Then shutoff the drain valve and turn on the cold water supply. Allow the tank to fill before you turn on the electric or gas. Once you hear the HW heater start up, then you’re DONE!

How frequently should you drain your tank?

This depends on the source and purity of your water supply. Some pros recommend doing this annually, some every few years and still others think this isn’t necessary. I recommend that you flush your tank annually, even if it’s a partial drain to clear the sediment from the bottom of your tank. Just remember that with an electric Hot Water Heater, you need to shut the power off. Because even a partial drain can expose the top heating element, which can damage it!

Next time we'll look at Weather Striping, which helps reduce Drafts. Until then have a wonderful week.