Bradford White · AeroTherm (RE2H…-1NCTT models)
Bradford White AeroTherm (RE2H…-1NCTT models) error code Fd
What it means
Control checks to ensure evaporator superheat is OK (controlled by EEV). Continuously verifies the temperature difference between T3a sensor (evaporator inlet temperature) and T3b sensor (evaporator outlet temperature) is greater than 5°F after 30 minutes of run time. Control also verifies that T3a is greater than 10°F less than T5 ambient sensor.
The manual says the control must detect this 10 time(s) before the code is displayed.
What Bradford White says to do
Contact a certified technician to assess and repair the water heater based on the fault codes.
Last checked 2026-10-03.
Safety first
- DANGER: Shut OFF power to the water heater before draining water to avoid risk of shock. (p.23)
- CAUTION: For your safety, do NOT attempt to repair the water heater or any of its parts. Refer any repairs to a qualified service technician. (p.22)
- Fault codes should only be used to help identify components which require testing. Never replace a part based solely on a fault code. The control can generate a false fault if the right conditions exist. (p.28)
From the manufacturer's manual for this series.
The same code on other models
Codes mean different things on different heaters. Match the series to the model number on your rating label.