5 Flashes
Bradford White Water Heater
Severity: ModerateWhat Does This Error Mean?
Bradford White 5 flashes points to a fault in the gas valve circuit — typically a defective gas valve or a wiring issue between the valve and the thermopile.
The control sees an unexpected reading on the valve output and refuses to fire the burner.
The fix usually starts with reseating the wiring, then testing components if the fault persists.
Affected Models
- Bradford White Defender
- Bradford White ICON gas valve models
- Bradford White RG series
- Bradford White M-I series
Common Causes
- Loose terminal at the gas valve
- Thermopile producing low voltage but not yet at 2-flash threshold
- Damaged wire between thermopile and gas valve
- Gas valve internal coil failed
- Moisture on the gas valve connector after a flooded basement
How to Fix It
-
Power and gas off.
Turn the gas valve to OFF.
Let the burner area cool.
The gas valve and thermopile carry only low-voltage signals, but tightening connectors safely needs a cool unit. -
Reseat all valve terminals.
Open the burner access cover.
At the gas valve, look at every wire connected to it.
Pull each connector, wipe with a clean cloth, and reseat firmly.
Loose terminals after years of vibration cause many 5-flash codes. -
Test thermopile output.
Light the pilot.
Measure millivolts at the thermopile terminals on the gas valve.
650-850 mV under load = healthy.
Below 400 mV = thermopile failing — replace it (25-60 USD). -
Inspect wiring runs.
Look at the wire between thermopile and gas valve, and between the temperature sensor and the valve.
Chafed insulation, kinks, or rodent damage all show up here.
Replace damaged sections rather than tape over them. -
Replace the gas valve.
If wiring and thermopile are both good and 5 flashes returns, the gas valve electronics have failed.
Bradford White ICON valves are 200-400 USD.
This is a plumber-level job — pipe dope, leak test with soapy water, follow the lighting sequence. -
Leak test before relighting.
After any gas valve work, brush soapy water on every joint.
Open the gas supply.
Bubbles = leak.
Tighten or redo until clean.
Frequently Asked Questions
How do I tell if it is the valve or the thermopile?
Test thermopile millivolts first — if low, it is the thermopile.
If thermopile is healthy and connections are clean, the valve is the suspect.
Skipping the millivolt test risks throwing parts at the problem.