How to mothball a hot water heater?

[Spud]

I bought a house that will remain unoccupied for 1 year or more while I do a rennovation. How should I go about mothballing the hotwater tank. It's a 40 gallon 2009 tank (can't remember the brand) with a vacation mode.

1) Do I just shut off the gas & water & then drain the tank or is there more to do?

2) Should I just leave it on vacation mode for an extended period of time?

3) What would it cost me / month to just leave it running on its lowest normal temperature.

Thanks,
Spud

 

[phishfood]

I would flush the tank to remove any sediment, then shut off the gas and water and drain the tank. A 2009 water heater should not be in any real danger of failing and leaking, but it won't hurt to have the water off, and with the tank drained, bacteria won't have a chance to grow in the water.

 

[Spud]

How should I go about flushing the tank?

 

[phishfood]

There should be a valve on the bottom of the water heater that you can attach a garden hose to. Run the garden hose to a suitable location, such as outside, and open the valve. With the supply pressure on to the water heater, any sediment that is in the bottom of the tank will be forced out of the drain valve. After the water has been coming out clear for several minutes, open the hot side of a couple of fixtures in the house, and then shut the supply valve to the water heater off. This should allow the tank to drain empty. Make sure you shut the gas or electric supply off BEFORE you drain the tank.

When you are ready to put the water heater back in service, turn the supply back on, and release the air from the tank through the hot side of several fixtures. Once the tank is full and no more air is evident in the hot water at the fixtures, turn on the gas and relight the pilot, or turn the breaker back on if it is an electric unit. Make sure to recheck that the drain valve you used to flush and drain the tank is not leaking.

 

[Spud]

Phishfood - great reply. thanks.

Will the left over moisture in the tank grow algae that will need to be cleaned / flushed with chemicals or will running a few tank fulls of clean water upon restart be enough to clean it out?

 

[havasu]

I myself would supplement the drain of the tank with the addition of a few drops of household bleach per remaining gallon of water to reduce algae and bacteria growth.

When you are ready for firing the tank back up, a quick flush will make your W/H be fresh and sanitary.

 

[Spud]

I like the bleach idea. How would I get the bleach into the tank?

 

[havasu]

The easiest way is to drop it into your cold water intake at the top of the heater.

 

[Tech]

When relighting the pilot flame remember to hold down the button for about 5-10 seconds after the pilot light is lit