Restart the water heater

The procedure

1. Make sure the drain valve is closed. Look at the valve near the bottom of the tank. If the plumber left a hose on it, take it off.
2. Fill the tank. With the water back on (see OD-1), open the cold supply valve at the heater fully.
3. Bleed the air. Open a hot tap in a nearby bathroom and leave it until water runs without sputtering. That tells you the tank is full.
4. Electric heater: power on. Switch the heater's breaker back on only now. An empty electric tank can burn out its elements in seconds.
5. Set the temperature. The U.S. Department of Energy and the CPSC both point to 120°F as enough for most households and safer against scalds.
6. Check the relief valve pipe. The pipe from the temperature-and-pressure relief valve should be dry and run down to near the floor or a drain. Never cap or plug it.
7. Plumber's step — gas heaters: if the gas supply or the heater was shut down for winter, have a licensed plumber or South Jersey Gas relight it. If gas service was turned off at the meter, South Jersey Gas says not to turn it back on yourself.

Why must an electric tank be full before the power goes on?

The heating elements sit inside the tank and are cooled by water. Powered while dry, they overheat and fail almost at once, a costly and avoidable mistake on a drained house.

What temperature should a shore-house heater be set to?

120°F is the figure the Department of Energy gives for most homes, and the Consumer Product Safety Commission recommends it to cut scald risk. Renters and young children are a good reason not to go higher.

What if the heater sat in a flooded space?

Don't use it. Water heaters that were under floodwater need a licensed pro to inspect or replace them. See AS-2.

The numbers behind it

Questions owners ask

How long does a tank take to heat after winter?

Often an hour or more, depending on size and type. Check the maker's label for recovery time.

Can I relight the pilot myself?

This manual leaves gas relighting to a licensed plumber or the gas utility, especially after a long shutdown or any flooding.

Why is my hot water rusty in spring?

Sediment settles in a tank that sat all winter. Run the hot taps until clear; if it stays rusty, have the tank checked.

Should I flush the tank at opening?

Draining and flushing a gas heater is a plumber's job on this site. On an electric tank, follow the maker's manual or ask the plumber at the spring visit.