Water Heater Reset Buttons & Controls

Locations of the reset switch for all types of water heaters

Reset Button Location on Electric Water Heaters

The reset button or buttons on an electric water heater or calorifier is found on the thermostatic control(s) under a removable metal cover. On smaller calorifiers (or geysers, depending on where you live). there will be just one of these thermostatic controls.

But on most large, tall electric water heater cylinders like the HB Smith electric water heater in our photo above, there will be two thermostatic controls, one for an upper, and one for a lower heating element.

Above our photo shows us removing the cover to expose the water heater control thermostat.

Watch out: on an electric water heater, when you remove its cover and perhaps also pull out a styrofoam or other plastic insulating block (in my hand in the photo), you are going to expose live electrical contacts. If you touch those wires or the exposed wire connector screws (shown in our close-up below) you could be shocked or killed.

That's why, in the photo above, the manufacturer included that gray plastic cover over the control. The cover leaves the red reset button accessible but it tries to cover up the electrical wires and their connections.

That red button at the top of the control might trip - pop out a bit - and can be reset by pushing it back in.

Really? Well no. Not right away. If the button tripped because it was doing its job - the water temperature was dangerously high - then you may not be able to re-set this button until the water heater has cooled down.

A closer look at the electric water heater high temperature shut-off reset button is below.

Note: even if there are two electric heating elements on your water heater, it's possible that only one of them sports a reset switch.

For more information,

see ELECTRIC WATER HEATER HIGH TEMP CUTOFF TEST

Reset Button Locations on Gas Fired Water Heaters / Geysers / Calorifiers / Cylinders

Gas fired water heaters may trip off for more than one reason, so we have some things to check if your gas water heater is "off".

Watch out: There is no single "reset button" on these water heaters. In our illustration of a Rheem LP gas water heater control below, that square red button under the pilot / temperature control is the igniter button used to light the pilot: it is not a reset button.

On other gas fueled water heater controls you may find a knob that must be turned to "pilot" and held down while lighting a pilot. That's not a "reset" button either.

OK, so if there's no "reset button" that popped on a gas water heater, what do we look for if the heater is "off" when we think it should be working?

Gas water heater off: no fuel?

Perhaps the first thing to check if your LP gas fueled hot water cylinder (water heater) is "off", is whether or not the pilot is lit.

The second thing to check, if there is no gas flame or no gas pilot, is whether or not you have run out of fuel (LP gas) or if the gas supply has been turned off (natural gas).

Gas water heater off: no pilot?

If your geyser (water heater) uses a standing pilot ( a small flame at the burner that is always "on") and if that flame is off, then you might simply need to re-light the pilot.

See GAS BURNER PILOT LIGHT PROCEDURE

Gas water heater flame monitoring: thermocouple control

If the pilot won't stay on, you may need to replace a bad thermocouple.

See THERMOCOUPLE REPAIR / REPLACEMENT

Gas water heater flue gas spill switch

Some water heaters include a flue gas spillage detector found on the draft hood at the water heater top.

If the chimney is not venting flue gases safely, to reduce the risk of fatal carbon monoxide poisoning of the building occupants, this device senses that flue gases are spilling out at the water heater top and it will shut off the gas control.

Often there is a small reset button right on the flue gas spill switch itself.

Watch out: flue gas spillage can be a fatal hazard in buildings. Be sure that you have working carbon monoxide (CO) detectors properly installed, located, tested.

See FLUE GAS SPILL SWITCH TRIPPING & RESET.

Gas water heater temperature control?

Water temperature for gas water heaters is usually on a dial found on the heater's main gas control valve.

As we noted earlier, there is no re-set switch on many typical gas fired water heater temperature controls, but we include a photo of that control for your information, below.

[photo due]

For more information about gas water heaters see

• GAS FIRED WATER HEATERS - home

   

Reset Button Location on Oil Fired Water Heaters

Oil Water Heater Off: Aquastat Control Reset

Our photo above shows an oil fired water heater whose primary control and temperature sensor are mounted above the oil burner itself - red arrow.

...

The location may be on the oil burner motor, on the oil burner primary control or aquastat (the red button pointed to by our green arrow on the control shown above).

For more information on resetting an aquastat primary control,

see AQUASTAT RESET BUTTON 

Oil Water Heater Off: Cad Cell Relay Tripped

The oil burner may have been switched off if a cad cell sensor didn't detect a sound burner flame - an oil burner cad cell relay is shown below.

For more information on the reset button on cad cell relays like the one shown,

see RESET SWITCH, CAD CELL RELAY - home

and

see RESET SWITCH, PRIMARY CONTROL.

Oil Fired Water Heater Off: Stack Relay Tripped

Some older oil fired water heaters may use a "stack relay" - a safety control that is mounted on the exhaust flue rather than on the heater itself, as you can see in our photo below.

Re-setting a stack relay, called "re-stepping the stack relay control" is not difficult, but it's trickier than just pushing a button.

At STACK RELAY SWITCH  we explain how to re-set this control.

Other Reasons the Oil Burner May be "Off" on Reset or just "Off"

An oil burner might be "off" for other reasons, too, including

• You've run out of heating oil - check the level of fuel in the oil tank
• The oil burner needs service and is running poorly, being shut off, for safety, by its primary control
• The oil burner's electric motor is failing

Watch out: don't keep pushing the reset button on oil burner safety controls. If the oil burner does not keep running for hours or longer after a reset, and if you keep pressing the reset button you could cause a dangerous puff-back explosion.

Instead, call your oil heat service technician for help.

Below: a typical electric motor found on oil burners.

see RESET SWITCH, ELECTRIC MOTOR

If you're still stuck and your oil burner won't start or won't keep running, see the diagnostic steps

at OIL BURNER WONT RUN 

and, of course, call your heating service company for more help.

Reset Button Location on Indirect Fired Water Heaters

Indirect water heaters are tanks of hot water whose contents are heated by an internal coil through which hot water is circulated from a separate heating boiler that may be in use for central heating in the same building.

So if your indirect water heater is "off", correction may require resetting an aquastat that controls the boiler that heats the indirect fired water heater.

But those controls will vary too, depending on the energy source used: oil, gas, electric - as outlined above on this page.

So start by identifying the primary source of heat for your indirect water heater, then check

to see if the main heater is running normally. If it is, then

check to see if the aquastat on the indirect water heater is calling for hot water - that should run a circulator that reheats the indirect water heater

Details are

at INDIRECT FIRED WATER HEATERS

and

at INDIRECT WATER HEATER TEMPERATURE CONTROLS

Reset Controls on Tankless Water Heaters

The nice news for people whose hot water is provided by a tankless water heater is that most of these units include controls that will automatically self-reset.

At most, you might have to turn power to the heater off, wait a few minutes, then turn power back on.

See details

at TANKLESS WATER HEATER REPAIR GUIDE