Water Heater Blinking Light: 2, 4 and 8 Blinks by Brand
By Ray Bennett · Updated 2 October 2026 · 5 min read · Checked against the makers’ own manuals 
On a gas water heater's control, one slow blink is normal, 2 blinks is a weak pilot or thermopile and 4 means the water got too hot. Those agree across Honeywell, Rheem and Bradford White controls. 8 blinks does not agree, and on a Whirlpool electric heater 2 red flashes means something else entirely. Read your brand's own list.
The small light on a gas water heater’s control is how it tells you what is wrong. It blinks a count, pauses, and repeats. On gas tank heaters the counts agree more often than they do on furnaces, but not always, and an electric heater counts on a different scheme altogether.
This page brings together what the makers’ own manuals say, as quoted on this site’s brand pages. Every brand-specific line here comes from the manual cited on that brand’s page.
Before you start
What to carry: a torch and a pen. Five minutes.
Gas or electric? Mostly gas: the blinking status light sits on the gas control of a gas tank heater. The electric and tankless codes are further down.
Whose control is it? The maker’s name is on the gas control on the front of the heater. Many A.O. Smith and Bradford White tanks carry a Honeywell control, and Bradford White also uses White Rodgers and its own ICON System.
Count after the pause. Bradford White counts its blinks after a three second pause, Honeywell repeats its count after a three second pause, and Rheem gives a number of blinks every three seconds.
A pilot that will not go out. Bradford White’s ICON code 8 means the pilot valve is stuck open with the knob at Off. Turn the gas off at the supply valve and call for a new control.
No light and a cold tank. On these controls the light is powered by the pilot, so the pilot must be lit before any code can show: how to light a water heater pilot.
The counts that agree
Read the count
1 blink: normal. Honeywell and Rheem blink once every three seconds when the pilot is lit and all is well. Rheem’s blink is blue.
2 blinks: the pilot or thermopile. Honeywell, Rheem and Bradford White all read it as low thermopile voltage, or a weak pilot. Look at the pilot: a small or lazy flame cannot make enough power.
4 blinks: too hot. All three say the water got too hot and the control shut down on its temperature limit. Bradford White says to turn the knob to Off and wait at least five minutes before relighting.
5 blinks: the sensor. Honeywell, Rheem and the ICON System read it as the water temperature sensor. On Bradford White’s White Rodgers control, it covers electronics, the sensor or the gas valve.
7 blinks: the control. Honeywell calls it an electronics failure, Rheem a gas control or valve failure, and Bradford White a gas control electronic fault.
The counts that do not agree
| The light | What it means, by control |
|---|---|
| 8 blinks | Honeywell: a warning, the control still sees power with the knob at Off. Rheem: a flame sense error, a pilot flame signal it should not see. Bradford White ICON: the pilot valve stuck open. |
| Steady on | Honeywell: the knob was turned to Off and the control is shutting down, wait about a minute. Rheem: the pilot recently went out or the knob was just turned Off. |
| 3 and 6 blinks | Only on Bradford White’s ICON System: 3 is not enough heating, and 6 is a water leak when its leak module is fitted. |
| 2 red flashes | On a Whirlpool Energy Smart electric heater, the water went over the high limit, not a thermopile. |
Electric heaters count differently
Know which scheme you have
Whirlpool Energy Smart. Its electronic thermostat flashes a red count that matches the E code on the front panel: 1 is a dry tank, 2 the high limit, 4 and 5 the upper and lower element circuits.
Its reset. For E02, Whirlpool says breaker off, press the red reset button on the thermostat, then breaker on: the Whirlpool Energy Smart codes.
An electric tank with no status light is checked at its reset button and its elements: how to test an element.
Find your heater’s full list
| Heater | How it shows codes | The full list |
|---|---|---|
| Gas tank, Honeywell control | Blinks, then a three second pause | Honeywell status light |
| Gas tank, Rheem | Blue and red blinks | Rheem status light |
| Gas tank, Bradford White | Blinks after a pause | Bradford White codes |
| Electric, Whirlpool Energy Smart | E codes and red flashes | Whirlpool codes |
| Heat pump, GE GeoSpring | F codes on a display | GeoSpring codes |
| Heat pump, Rheem | A and T codes | Rheem hybrid codes |
| Heat pump, A.O. Smith | Letter codes | A.O. Smith hybrid codes |
| Tankless, Rinnai | Two digit codes | Rinnai codes |
| Tankless, Navien | E codes | Navien codes |
| Tankless, Noritz | Number codes | Noritz codes |
| Tankless, Takagi | Number codes and red flashes | Takagi codes |
| Tankless, Rheem | Number and A codes | Rheem tankless codes |
| Electric tankless, EcoSmart | E codes, or letter and number messages | EcoSmart codes |
When there is no light at all
Start with the pilot
The pilot is out. On Honeywell, Rheem and Bradford White controls the light needs the pilot. Relight it with the label on the heater, and give the control time after turning the knob to Off.
It will not stay lit. Rheem says to keep the knob pressed in until the pilot is lit and the code can be read. A pilot that goes out again points at the thermopile: why a pilot keeps going out.
No hot water, no clue. Start from the top: the water heater checks in order.
Questions people ask
Why is my water heater light blinking?
The gas control is counting out a code. Count the blinks between pauses and look them up for the maker of the control. One slow blink is normal.
What do 2 blinks mean on a water heater?
On Honeywell, Rheem and Bradford White gas controls, low thermopile voltage or a weak pilot. On a Whirlpool Energy Smart electric heater, 2 red flashes means the high limit.
What do 4 blinks mean?
The water got too hot and the control shut down. Bradford White says to turn the knob to Off and wait at least five minutes before relighting, and to set the temperature lower.
What do 8 blinks mean?
It depends on the control: power with the knob at Off on Honeywell, a flame sense error on Rheem, and a pilot valve stuck open on Bradford White’s ICON.
Why is the light on steady?
On Honeywell and Rheem controls, the knob was just turned to Off or the pilot has just gone out. Honeywell says wait until the light goes out, about a minute, before relighting.
Why is there no light at all?
On these gas controls the light runs on power the pilot makes. No pilot, no light, so relight it first.
Sources: The makers' own documents, as cited on this site's brand pages: Resideo (Honeywell) WT8840, Rheem AP23698, Bradford White service manual 238-51542-00 and Whirlpool 318686-001
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