Count the flashes, wait for the three-second pause, and count again to be sure. On a standard atmospheric-vent tank the light sits on the ICON gas control, which Honeywell (now Resideo) builds for Bradford White, and the control is powered entirely by the pilot flame through a thermopile. The first-generation ICON flashes once with a three-second pause when all is well. The second generation and the White-Rodgers control on some models flash once every four seconds at rest and once a second while the burner is lit, and the ICON V2 light changes colour: green for normal, yellow for low thermopile voltage, red for a valve fault.
Because the pilot powers the electronics, a dark control means there is no pilot or no thermopile output. Follow the pilot relight steps printed on the tank. If the pilot lights and will not hold, the usual cause on a Defender Safety System model is underneath: lint, dust or oil has built up on the ScreenLok flame arrestor, the burner is short of air, and the resettable thermal switch on the inner door has opened. That switch has a red button in its centre, but pressing it without cleaning the arrestor and finding why it tripped only buys a few hours.
Power-vent models, the TTW series with a blower on top and a cord in the wall, use a different electronic gas control with a pressure switch and a spark-lit pilot. Their codes overlap in number but not in meaning, so they are listed separately below with a PV prefix. Flash codes vary by model and by control generation, and Bradford White prints the legend for your heater on the tank: that label wins over this page. Our Bradford White water heater repair page covers the models we see most, and you can reach ZK Mechanical here with the count you are seeing.
Bradford White water heater codes, decoded
| Code | What it means | Safe? | Try first | When to call |
|---|---|---|---|---|
No light | Pilot is not lit, or the thermopile is not generating enough to power the control. | turn it off | Relight using the instructions on the tank. Smell gas at any point: stop and leave the house. | If the pilot will not light or will not stay lit after two tries. |
1 flash, repeating | Normal. The pilot is lit and the control is either satisfied or heating. | keep running | Nothing to do. Set the knob to the temperature you want. | Only if there is no hot water despite a normal light. |
Solid on | Not an error. The knob was recently turned to OFF and the control is shutting down. | keep running | Wait until the light goes out before trying to relight. | No call needed. |
2 flashes | Weak pilot signal: low thermopile voltage, an unstable pilot, or a blocked pilot tube. The main burner will not light. | keep running | Look through the sight glass for a steady pilot. Vacuum lint from around the base of the tank. | Soon. There is no hot water until the pilot assembly is sorted out. |
3 flashes | Insufficient water heating (ICON V1). The control resets itself, but Bradford White's procedure is to replace the gas control. | keep running | None. | Book a repair if the count repeats over several days. |
4 flashes | Excessive tank temperature. The cut-out limit was reached and the control has shut down. | turn it off | Turn the knob to OFF. Do not try to reset and relight. | Yes. On these tanks the service procedure is a new gas control. |
5 flashes | Temperature sensor fault: the sensor is damaged, unplugged or out of range. On ICON V2 and White-Rodgers controls it covers any electronics, sensor or valve fault. | turn it off | Check whether the control or its wiring has been splashed or is sitting wet. | Yes. The sensor is tested first, then the control. |
6 flashes | Water leak detected by the accessory leak module (ICON V1 with that module fitted). | turn it off | Look in the drain pan and at the fittings on top. Close the cold supply valve if water is collecting. | Same day. The relief valve, fittings and tank are leak-tested. |
7 flashes | Gas control electronic fault. The control needs resetting, or it is wet or physically damaged. | turn it off | None. | Yes. A reset is tried once; if 7 returns the control is replaced. |
8 flashes | Standing pilot remains on with the knob at OFF. The pilot valve is stuck open. | call now | Close the gas shutoff on the pipe feeding the water heater. | Immediately. A valve that will not close gets replaced, not adjusted. |
PV: 1 flash per second | Power-vent control: weak pilot signal on the last call for heat. On these models a slow flash every four seconds is the normal standby signal. | keep running | None, but note it down. | Book a service visit. The pilot electrode oxidizes over time. |
PV: 2 flashes | Pressure switch stuck in the closed position before the blower starts. | turn it off | None. | Yes. Kinked tubing, a blocked tap or a failed switch. |
PV: 3 flashes | Pressure switch or blower temperature switch will not close: vent blockage, wrong vent configuration, a slow blower, or exhaust running too hot. | turn it off | Check the vent termination outside for ice, snow or a nest. Make sure the heater is plugged in. | If the termination is clear and three flashes continue. |
PV: 4 flashes | Excessive tank temperature on a power-vent model. The system must be reset by a technician after the sensor and control are tested. | turn it off | Switch the control off and leave it. | Yes, before it heats again. |
PV: 5 flashes | Undesired pilot flame present: the control senses a pilot when none was called for. | call now | Unplug the heater and close its gas shutoff. | Immediately. |
PV: 6-1 or 6-3 | Six flashes then one: failed to light the pilot. Six then three: pilot flame went out. Both retry automatically. | turn it off | Confirm the gas is on to the house. | If it keeps cycling. Pilot tube, electrode, combustion air or gas pressure. |
PV: 6-2 | Pressure switch or blower temperature switch opened while the burner was running. Wind on the vent termination is one listed cause. | turn it off | Note whether it happens only on windy days, and check the termination. | If it repeats in calm weather. |
PV: 7 flashes | Flammable vapour sensor fault detected. | call now | Move gasoline, solvents and paint out of the room and ventilate it. | Immediately. The sensor is tested before the heater is restarted. |
PV: 8-1 to 8-4 | Eight flashes then a second count: 8-1 vapour sensor out of specification, 8-2 temperature sensor fault, 8-3 electronics fault, 8-4 gas valve fault. | turn it off | Unplug for a minute and plug back in, once. | If the same two-part count comes back. |
The codes that usually mean a real repair
No light or 2 flashes: pilot, thermopile and the ScreenLok arrestor
This is the everyday Bradford White call. The thermopile weakens with age, the pilot tube picks up debris, or the flame arrestor under the tank is matted with laundry-room lint and the thermal switch has opened. The visit covers cleaning the arrestor plate and the jacket air openings, testing the thermopile output and replacing the pilot assembly if it is low. Pilot-side repairs of this kind usually land in the $150–$300 band, quoted before any part goes in.
4, 5 or 7 flashes: the gas control
On the atmospheric models Bradford White's service procedure for a four-flash over-temperature code is to replace the gas control, not to reset it and walk away, and a five or seven that survives one reset ends the same way. A gas control replacement runs $400–$600. On a tank past ten years old, weigh that against a straight tank-for-tank swap at $1,200–$2,500. What four flashes on a water heater status light mean goes further into the overheat side.
PV 3 flashes or 6-2: pressure switch, vent and blower
A power-vent tank will not open its gas valve until the pressure switch proves the blower is moving air through the vent. Ice on the termination, a sagging vent run holding water, a kinked sensing tube or a tired blower all end in the same count. We check the vent against Bradford White's vent tables and measure the switch before replacing anything. There is no flat price for this one: the $90–$150 diagnostic is credited and the repair is quoted in writing.
Licensed technicians, a written price before the repair, no overtime charges.
Common questions
Why does my Bradford White flash once every second?
It depends on which heater you have. On an atmospheric tank with an ICON V2 or White-Rodgers control, one flash a second simply means the main burner is lit. On a power-vent TTW model, a short flash once a second means the control saw a weak pilot signal on the last heating cycle and wants attention. Check for a blower and a power cord before deciding which meaning applies.
What is the red button on the bottom door of a Bradford White?
That is the resettable thermal switch. It opens when the combustion chamber overheats, which happens when the flame arrestor is choked with lint or dust, when the room is short of combustion air, or after a flammable vapour incident. Bradford White's manual says the cause must be found before the heater goes back into service. After a vapour incident the instruction is to replace the water heater.
My status light is yellow or red instead of green. What changed?
You have the second-generation ICON control, which adds colour to the count. Green is normal operation and yellow with two flashes is low thermopile voltage. Red with four or five flashes is a valve-side fault: the temperature cut-out or the electronics and sensor. A solid red light is only the control shutting down after the knob was turned to OFF.
Can I keep relighting a pilot that goes out every few days?
Relight it once and watch. A pilot that keeps dropping out has a cause: a failing thermopile, a draft problem, or a thermal switch that keeps opening because the burner is starved for air. Repeated relights hide a fault that tends to get worse. If the tank is rented, the rental company owns that repair; if it is yours, book it through our water heater service.
Does the Bradford White guide apply to an A. O. Smith tank?
Only loosely. Both brands use a status light gas valve on their standing-pilot tanks and several counts line up, but the legends are not identical: eight flashes, for instance, is worded differently, and the power-vent controls are unrelated. Use the A. O. Smith water heater error code guide for that brand and the label on the tank for the final word.