- Water Heaters
- Water heaters
- How-to
- 6-minute read
Leaks, vacations, a flooded basement, a repair you are about to make — each one starts with the same 120 seconds at the tank. Here is the order for gas and electric units, and the one mistake that damages a tank.
To turn off water heater fuel on a gas unit, rotate the gas control knob from ON to PILOT (keeps the pilot lit) or OFF (leak or gas smell). On an electric unit, switch off its two-pole breaker at the panel. Then close the cold-water inlet valve above the tank. Never power an electric heater with the tank empty.
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Key takeaways
- Gas: PILOT for a vacation or a repair, OFF for a leak or a gas smell. Electric: breaker off, always.
- The cold inlet valve stops water entering the tank; the T&P valve and a hot faucet relieve pressure.
- Draining is a separate step and only needed for a repair, a long winter absence in an unheated space, or a replacement.
- Restarting is in reverse: fill first, then power or gas. The turn-on guide covers it.
Shutting down a gas unit: how do you turn off water heater gas safely?
Find the gas control
The box at the base of the tank with a temperature dial and a knob or switch marked OFF / PILOT / ON.
Choose PILOT or OFF
PILOT stops the main burner but keeps the pilot flame lit, so relighting is not needed later. OFF closes the gas entirely — use it for a leak, a gas smell, or when the tank will be drained.
Close the gas shutoff if you smell gas
The lever valve on the gas line feeding the tank: a quarter turn so the handle sits across the pipe. Then leave the house and call the gas utility from outside. A drain backing up at the same time is a separate emergency drain service in Racine call, not a heater problem.
Close the cold inlet
The valve on the cold pipe entering the top of the tank. Clockwise, or a quarter turn for a lever.
Relieve the pressure
Open a hot faucet somewhere in the house for a minute. That is enough for a shutdown; a full drain is only needed for repairs, per the draining guide.
Killing power to an electric tank: how do you turn off water heater power?
Go to the breaker panel
The water heater is on a two-pole breaker, usually 30 amps, often labeled. Switch it fully off. If nothing is labeled, look for the double-width breaker.
Confirm at the tank
Some installations have a disconnect switch near the heater; turn that off too. A non-contact tester at the access panel confirms the elements are dead.
Close the cold inlet
Same as gas: the valve on the cold pipe at the top of the tank.
Never power an empty electric tank
Elements burn out within seconds if they heat air. Whenever the tank is drained, the breaker stays off until it is refilled and a hot faucet runs steady — the sequence in the turn-on guide.
Some 1950s and 1960s houses have the water heater on an unlabeled breaker or a fuse block. If turning off the only likely breaker does not kill the heater, stop and call rather than pulling fuses at random.
When is a full shutdown the right move?
Leak, gas smell, or flooding
Gas to OFF and the gas shutoff closed; electric breaker off before anyone steps in water. Then the cold inlet. The leaking tank guide covers what comes next.
Repair or element test
Power or gas off and the cold inlet closed before opening any panel or touching the drain valve. The element test guide starts here.
Vacation
Gas to PILOT or the VACATION setting; electric breaker off. Leave the cold inlet open unless the house will be unheated, in which case drain it.
A whole-house water emergency — a burst pipe — starts at the main instead. The guide to finding the main water shut-off covers that valve.
Weekend away: worth shutting it off?
For two or three days, no need to turn off water heater power at all. A modern tank loses little heat on standby, and a gas unit on PILOT still keeps the pilot burning. The savings are small and the relight or the cold morning after is the trade.
For a week or more it makes sense, especially in winter when a Racine basement is cold and standby losses climb. PILOT or VACATION on gas, breaker off on electric. In an unheated house, drain it as well so nothing freezes.
Shut it down for a leak and now unsure whether it is safe to restart? PM checks the tank, the T&P valve and the connections before it goes back on.
Call (262) 770-0039Request serviceWhat goes wrong during a shutdown?
- Turning OFF when PILOT would do. Not harmful, but relighting an older standing-pilot unit is a chore; the pilot light guide walks through it.
- Draining with the power on. The most common way an electric element dies. Turn off water heater power at the breaker first, every time.
- Forcing a seized inlet valve. An old gate valve that will not turn gets replaced, not wrenched; use the main in the meantime.
- Opening the T&P valve to drain. It is a safety valve, not a drain, and it often will not reseat afterward. Use the drain valve at the base.
- Restarting before the tank is full. Gas units tolerate it briefly; electric units do not.
If the tank is old enough that a shutdown turned into a leak — common on units past ten years — the water heater repair and replacement service quotes both options on the same visit.
Shutdown questions PM answers by phone
Do I need to turn off water heater power before draining a few gallons to flush it?
On an electric heater, yes — the lower element sits near the bottom and can be exposed as the level drops. On a gas heater, set the control to PILOT so the burner does not fire on an emptying tank.
Is it dangerous to leave the gas on PILOT for weeks?
No. PILOT is a normal standby state; the pilot flame is tiny and the main burner cannot fire. It uses a small amount of gas, which is why some people prefer OFF for long absences.
Can I turn off the water heater and still have water?
Yes. Shutting the gas or breaker only stops heating; every cold faucet keeps working, and hot faucets run cold once the tank cools. During a water main break, shut the heater off and close the cold inlet so air and sediment from the main do not enter the tank.
What if I cannot turn off water heater gas because the knob is stuck?
Some controls require pushing in slightly while turning; others have a lock. If it is stuck, close the lever valve on the gas line instead and have the control checked — a stiff control is often a control near failure.
Can I turn off water heater supply at the cold valve and leave the power on?
No. With the inlet closed and any hot faucet opened, the tank level can drop. Power or gas off first, then the inlet.
Restarting and related how-tos
Turning it back on has its own order — fill, purge air, then power. The guides below cover restart, relighting and testing.
Water heater off and something not right? Two Master Plumbers, same-visit repairs, free estimates on replacement across Racine County. If you are searching for plumbers near you in Racine, this is the shop that answers.
Call (262) 770-0039Request service