How to Reset a Water Heater: Electric, Gas and Tankless

By Ray Bennett · Updated 2 October 2026 · 6 min read · Checked against the makers’ own manuals

How to Reset a Water Heater: Electric, Gas and Tankless

Short answer

An electric tank has a red reset button behind its upper panel: breaker off, press it, breaker on. A gas tank has no button, and its reset is relighting: knob to Off, wait for the status light to go out, then light it again. A tankless heater resets at its power or its panel. A reset that trips again means the water got too hot, and that needs finding.

Which reset a water heater needs depends on what heats it. An electric tank has a red button. A gas tank has no button at all: its reset is relighting. A tankless heater resets at its power or its panel, and a heat pump model leaves its safety limit to a technician.

This page brings together what the makers’ own instructions say, as quoted on this site’s brand pages. One thing holds for all of them: a reset that trips again is a fault, not bad luck.

Before you start

What to carry: a torch, a screwdriver for the access panel and a pen. Fifteen minutes, plus the time the tank takes to heat.

Gas or electric? Both, and the reset is different for each. A gas heater has a gas pipe and a knob on the front. An electric one has a thick cable into the top and a panel or two on the side.

Write the code down first. Rinnai asks for the code when you call, Rheem says to note it before calling, and a reset clears it from the panel.

The resets never to do. If you smell gas. Do not light or reset anything. Leave and call from outside.

A button that trips again. The red button is the high limit, and it opens when the water gets far too hot. Whirlpool says to call a technician if it keeps shutting the heater off.

An overheat code on a tankless, again and again. Noritz warns that resetting its code 20 over and over without fixing the cause is likely to end in a 14, a thermal fuse that cannot be reset at all.

Power off before any panel. An electric tank runs on 240 volts. Switch the breaker off before the access panel comes off.

Where the reset is

Four kinds of water heater, four different resets. Only the electric tank has the red button people mean.

The heater	How the makers reset it
Electric tank	Breaker off, the red button on the upper thermostat, breaker on
Gas tank with a status light	Knob to Off, wait until the light goes out, relight
Navien tankless	The Back button on the front panel
Noritz tankless	Unplug for 20 seconds for code 16. Code 14 cannot be reset
Rheem condensing tankless	SERVICE, then ENTER, then Clear Alarms
Heat pump water heater	A tripped high limit is for a technician on Rheem and GE

Electric tank: the red button

Check 1Free, five minutes

Press the red button once

Where it is. Switch the breaker off. Take the upper access panel off the side of the tank and fold the insulation back. The red button sits on the upper thermostat.

Press it firmly until it clicks. Refit the insulation and the panel, switch the breaker on, and give the tank 60 to 90 minutes to heat, the time A.O. Smith gives an electric tank.

What tripped it. It is the high limit, often called the ECO. Whirlpool says its ECO trips above 180°F, far hotter than a tank should ever get: why a reset button keeps tripping.

Whirlpool Energy Smart. For E02, Whirlpool says breaker off, press the red reset button on the electronic thermostat, then breaker on. Once the power is back, it runs a system check that typically takes eight minutes: the Whirlpool codes.

Gas tank: the reset is relighting

The waits the makers give for a gas water heater. Rushing them is why a relight fails.

Check 2Free, fifteen minutes

Off, wait, relight

Count the light first. On Resideo, Bradford White and Rheem gas controls, a light blinks a code. Count it before you turn anything: what the blinks mean.

Knob to Off, then wait. A light that stays on means the control is shutting down. Resideo’s goes out in about a minute. Rheem says it can also mean the pilot has just gone out and the thermopile is cooling. After Bradford White’s code 4, wait at least five minutes.

Relight and hold. Follow the label on the heater. A.O. Smith says the thermopile can take up to 90 seconds to power the control, so keep holding the knob until the light shows the pilot is lit. On a Resideo control, that is one blink every three seconds.

A failed try. A.O. Smith says to turn the gas off and wait ten minutes before relighting: why a pilot will not stay lit.

4 blinks means too hot. On Resideo and Bradford White controls, it is the temperature limit. Turn the setting down. If it happens again, Bradford White has the temperature sensor tested, then the sensor or the control replaced.

Tankless: the power or the panel

Check 3Free, five minutes

Reset from the panel or the power

Navien. Navien says to press the Back button on the front panel. For minor problems, that alone may clear it: the Navien codes.

Noritz. For code 16, Noritz says unplug the heater for 20 seconds. Code 20, the high limit, needs a power reset. Code 14 is a thermal fuse and cannot be reset: the Noritz codes.

Rheem condensing models. Turn off the hot taps, press SERVICE then ENTER, go to Clear Alarms and choose Yes. If the code stays, Rheem says turn the heater off and call for service.

Takagi. Takagi’s guide includes resetting the computer board among its procedures. Turning the power off and on often clears a code, and if the cause is still there, it comes back.

Electric tankless after plumbing work. EcoSmart says to keep the power off and run hot water until it flows without air, then switch the breakers back on. Air can burn out the elements.

Heat pump water heaters

Check 4A service call

Leave the high limit to a technician

Rheem’s A200. Rheem says the ECO has tripped on high water temperature, and the heater stays disabled. Its display says to call tech service: the Rheem codes.

GE GeoSpring. GE says its manual reset limit, the TCO, should be reset by a qualified technician who finds out why it tripped.

The alarms you can clear. GE says press and hold FILTER to reset the filter alarm. Rheem says holding Clear Alarm for 5 seconds overrides the leak alarm for 24 hours, so look for the leak meanwhile.

Power off first. A.O. Smith says to turn the heater off at the breaker before cleaning the air filter or doing any maintenance.

Questions people ask

Where is the reset button on a water heater?

On an electric tank, behind the upper access panel, on the upper thermostat. It is red. A gas water heater has no reset button: its reset is relighting the pilot.

How do I reset a gas water heater?

Turn the knob to Off and wait until the status light goes out. Then relight it following the label, holding the knob for up to 90 seconds until the light shows the pilot is lit.

How do I reset a tankless water heater?

It depends on the brand. Navien uses the Back button on its panel. Noritz gives a 20 second unplug for code 16. Write the code down first, because a reset clears it.

Why does my water heater reset button keep tripping?

Because the water got too hot. Whirlpool’s ECO trips above 180°F. Pressing it again without finding the cause just waits for the next trip.

How long after a reset do I get hot water?

Give an electric tank 60 to 90 minutes, A.O. Smith’s figure. A Whirlpool Energy Smart runs a system check of about eight minutes before it starts heating.

Can I reset a heat pump water heater’s high limit myself?

Rheem and GE both leave it to a technician. Rheem’s heater stays disabled after an A200 until it is fixed.

Sources: The makers' own instructions, as cited on this site's brand pages: Whirlpool, Resideo (Honeywell), A.O. Smith, Bradford White, Rheem, Navien, Noritz, Rinnai, Takagi, EcoSmart and GE