Code: F4🚿 Bradford White Water Heater

Bradford White Error Code F4: Fan Failure (AeroTherm Heat Pump Water Heater)

Reviewed 2026-10-24 · Based on 3 manufacturer & service sources

What the code means

Bradford White's Installation and Operation Manual for the AeroTherm RE2H50S*-1NCTT, RE2H65T*-1NCTT and RE2H80T*-1NCTT (238-52169-00C) lists F4 in its fault code table as "Fan failure," with 10 fault counts before the code is displayed. The fan runs whenever the heat pump is working: in Hybrid and Heat Pump (Only) modes the heater pulls air through the filter on top of the unit, across the evaporator and out the back. During start-up the fan comes on after about 1 minute, keeps running with the compressor, and runs for 20 minutes after any compressor operation. Electric (Only) mode doesn't use the fan at all. Bradford White warns that fault codes only point to the components that need testing: never replace a part based solely on a fault code, because the control can generate a false fault if the right conditions exist, and a certified technician should assess the heater. F4 is different from F3 (compressor failure, no current detected) and from the dirty filter alarm (F14), which means the evaporator is running colder than the room air because the filter is too dirty. On the newer AeroTherm G2 series, Bradford White's manual 238-55123-00 and Quick Service Guide 238-55219-00 use code 8 (Fan Fault: the fan is not functioning properly, or could have a locked rotor) and code 98 (Fan Hard Fault: the fan is not functioning and operation cannot continue).

Likely causes

Safe DIY checks

⚠ Before you start

Turn off power at the furnace/HVAC service switch and the breaker before opening panels.

  1. Write down the exact code and your model and serial numbers from the rating label before calling for service.
  2. Clean the air filter on top of the unit. Bradford White says to leave the power on, squeeze the two tabs and lift the filter out, vacuum it, wipe it with a damp cloth or rinse it with warm water, let it dry, slide it back into the slots and hold the FILTER button to reset the filter alarm.
  3. Make sure nothing is sitting on top of the heater or blocking the air path. Bradford White recommends about 8 inches above the unit to remove the filter and 7 inches around the sides and back for service.
  4. If your unit is ducted, check that the ducts aren't crushed, disconnected or blocked.
  5. Until it's repaired, you can switch to Electric (Only) mode, which heats with the elements and runs without the fan, though it uses more energy.
  6. Don't open the unit's covers to get at the fan. Bradford White's manual says to refer repairs to a qualified service technician, and the heater runs on 240-volt power.

🛠 When to call a pro

  • Treat F4 as a pointer to test the fan circuit, not a parts order. Bradford White says never to replace a part based solely on a fault code.
  • Check the fan and its wiring and connections to the control, and confirm the rotor turns freely. Bradford White's IOM refers to the model's mini-manual for Service Mode functions, where component tests are done.
  • Confirm the fan starts about 1 minute into the start-up self-check and runs with the compressor, per the start-up sequence in the IOM.
  • Check airflow and installation: filter, required clearances, and for ducted G2 installs, total duct length (Bradford White's G2 limit is under 125 ft of flexible or 300 ft of rigid equivalent duct, 8 inch diameter unless a booster fan is installed).
  • Bradford White technical support is listed at 800-334-3393.

Parts that commonly fix it

Always match the part number to your exact model.

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Heat pump fan motor

Must match your exact model and serial number; a technician should confirm the fault and replace it.

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Air filter

The reusable filter on top of the unit; clean it first, replace only if it's damaged.

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Digital multimeter

For a technician's wiring and voltage checks; the unit runs on 240-volt power.

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Sources

  1. Bradford White AeroTherm Heat Pump Water Heater Installation & Operation Manual 238-52169-00C (RE2H50S/RE2H65T/RE2H80T -1NCTT): fault code table (F4 Fan failure, 10 counts; F3, F14 dirty filter), never replace a part based solely on a fault code, start-up sequence (fan on after 1 minute, runs 20 minutes after compressor), filter cleaning, clearances, Electric (Only) mode runs without the fan
  2. Bradford White Hybrid Electric Heat Pump Water Heater Installation and Operation Manual 238-55123-00 (AeroTherm G2): code 8 Fan Fault (locked rotor), 98 Fan Hard Fault, ducting length limits, long ducting reduces fan life
  3. Bradford White Quick Service Guide 238-55219-00 (AeroTherm Series heat pump water heaters): 8 Fan Fault, 98 Fan Hard Fault; Technical Support 800-334-3393

Last reviewed 2026-10-24. Always confirm against the manual for your exact model number.