Bradford White Water Heater Error Code 4 flash

The 4 flash error code on a Bradford White water heater indicates that the tank has reached an excessively high temperature. The gas control valve contains an integrated temperature sensor that continuously monitors the water temperature inside the tank. When this sensor detects a temperature that exceeds the safe operating threshold, the control board triggers the 4 flash fault code and shuts down the burner to prevent scalding, tank damage, or a potentially dangerous pressure buildup. Once this fault is triggered, the system will not resume normal operation until a manual reset is performed.

To reset the unit, the gas control knob must be turned to the minimum (or "pilot") setting and held there for at least 6 seconds before returning it to the desired temperature setting. This deliberate reset sequence is a safety interlock designed to prevent automatic restarts without technician or homeowner intervention. If the high-temperature condition caused the error, simply resetting without addressing the root cause will likely result in the fault recurring.

The three primary causes to investigate are a miscalibrated or faulty temperature sensor within the gas control valve, a malfunctioning gas control valve that is not properly regulating gas flow and is causing the burner to overheat the tank, and a plumbing crossover or check valve issue that could cause hot water to stagnate and build up temperature. Because the temperature sensor is integrated into the gas control valve assembly on most Bradford White models, a confirmed sensor failure typically requires replacing the entire gas control valve rather than the sensor alone.