Bradford White Water Heater Error Code 4 flash

The 4 flash code on a Bradford White water heater signals that the unit detected an excessively high tank temperature and shut down the burner as a safety precaution. The integrated temperature sensor in the gas control valve monitors water temperature continuously, and this fault is triggered when that temperature exceeds a safe threshold. The system requires a manual reset by turning the gas control knob to its minimum position for at least 6 seconds. If the code returns after resetting, further diagnosis of the gas control valve, temperature sensor, and plumbing is needed.

The fault code itself indicates the safety system worked correctly by shutting down the burner before temperatures could reach a truly dangerous level. However, the condition that caused excessive tank temperature should be taken seriously. A malfunctioning gas control valve that allows uncontrolled burner operation, or extreme overheating of tank water, can create risks including scalding and elevated pressure. Do not continue to reset the unit repeatedly without diagnosing and correcting the root cause.

The cost depends on the root cause. If the issue is a faulty gas control valve, which is the most common repair for this fault, replacement parts and labor typically range from $150 to $400 depending on the model and your location. If the problem turns out to be a plumbing-related issue such as a crossover or failed check valve, costs may be lower. Consulting a licensed plumber or appliance technician for an accurate diagnosis is recommended before committing to any parts purchase.

To reset the unit, turn the gas control knob to the minimum or pilot setting and hold it there for at least 6 seconds. After the 6-second hold, you can return the knob to your desired temperature setting and attempt to relight the pilot or restart the unit following normal startup procedures. Keep in mind that if the underlying cause of the overheating condition has not been resolved, the 4 flash fault is likely to return.

Resetting the unit will clear the fault and allow it to restart, but it will not fix the underlying problem causing the overheating. If the gas control valve is faulty, the temperature sensor is miscalibrated, or there is a plumbing issue contributing to the condition, the 4 flash code will likely return. A permanent resolution requires diagnosing and addressing the root cause, which may include replacing the gas control valve.