Bradford White Water Heater Error Code 34

Error code 34 means the control board has detected a fault with the combustion air temperature sensor. This sensor monitors the temperature of air entering the burner assembly, and the code is triggered when the sensor signal falls outside the acceptable range. The heater shuts down the burner as a safety response until the issue is diagnosed and corrected.

No. When error code 34 is active, the Bradford White control board has shut down the burner as a precautionary measure. The unit will not heat water normally in this state, and attempting to bypass the shutdown is not recommended. The combustion air temperature sensor is part of the safety system, and the heater should remain out of service until the fault is resolved.

Repair costs vary depending on the root cause. If the fix involves only cleaning the sensor or clearing an airflow restriction, costs may be minimal. If the combustion air temperature sensor needs replacement, parts typically range from around $30 to $80 depending on the model, with labor adding to the total if a technician is involved. Blower assembly components, if the fan blade or motor is damaged, will increase the repair cost further.

Some of the steps involved are DIY-friendly, such as checking for airflow restrictions around the unit and vent terminal, cleaning debris from the sensor, and inspecting visible wiring for damage. However, measuring sensor resistance and replacing internal components requires basic electrical knowledge and comfort working around gas appliances. If you are unsure about any step, contacting a qualified technician is the safer choice.

A reset may temporarily clear the error display, but if the underlying problem with the sensor, its wiring, or the airflow system has not been addressed, the code will return. Resetting without diagnosing the cause is not a fix. Work through the full diagnostic process, including sensor cleaning, wiring inspection, blower condition check, and airflow verification, before relying on a reset.