Bradford White · AeroTherm (RE2H…-1NCTT models)
Bradford White AeroTherm (RE2H…-1NCTT models) error code FL
What it means
Control checks to ensure that T3 and T3b evaporator inlet and outlet temperatures are within 2.5°F of the T5 ambient temperature 20 minutes after defrost begins.
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.