Bradford White Water Heater Error Code 29

Error code 29 on a Bradford White water heater indicates that the pressure switch failed to close during startup or became stuck in the open position during operation. The pressure switch is a safety component in the combustion air and venting system. Its job is to confirm that the inducer motor is generating adequate negative pressure (draft) before allowing the ignition sequence to proceed. When the inducer spins and creates proper airflow through the heat exchanger and vent system, the resulting pressure differential closes the switch contacts and signals the control board that combustion conditions are safe. If the switch never closes, or opens unexpectedly mid-cycle, the control board locks out and stores code 29.

The most frequent cause of this fault is a restriction in the exhaust or intake vent path. Debris, bird nests, ice, or collapsed piping in the vent terminal can prevent the inducer from building sufficient draft, which means the pressure switch never sees the pressure differential needed to close. In condensing water heaters, the condensate trap and drain line are equally important: a blocked or frozen condensate drain can allow water to back up into the pressure switch tubing or the heat exchanger itself, preventing proper draft and holding the switch open.

Beyond venting restrictions, the fault can also originate from a failed or degraded pressure switch, cracked or disconnected rubber tubing connecting the switch to the inducer housing, a weak inducer motor that cannot reach operating speed, or water intrusion into the pressure switch port. Diagnosing the root cause requires checking vent terminations, condensate drainage, tubing integrity, and motor performance before condemning the switch itself.