Mitsubishi Heat Pump: Indoor fan does not run
Indoor fan does not run on a Mitsubishi heat pump: The indoor blower will not turn. The fan motor is a DC motor fed about 310-340 V DC from the indoor board.
Applies to: PEAD-RP35/50/60/71/100/125/140JA and JA(L) ducted indoor units (220-240 V models)
Common causes of indoor fan does not run
- Blown fuse on the indoor board
- Drain pump shorted and taking out the fuse
- No DC supply from the board
- Loose fan motor connector CNMF
- Faulty fan motor or indoor board
How to fix indoor fan does not run: step by step
- WARNING: High DC voltage on connector CNMF. Never unplug it with power on - it can damage the board and the motor.
- Check the fuse on the indoor board. If it blew, check the drain pump resistance before replacing the fuse; a shorted pump must be replaced.
- With CNMF unplugged and power on, measure pin 1(+) to 4(-): about 310-340 V DC, and pin 5(+) to 4(-): about 15 V DC. Missing = replace the indoor board.
- If the supply is good, check CNMF for poor contact. If the connector is good and the fan still will not run, replace the fan motor.
If the unit shows an error code, look it up: Mitsubishi Heat Pump codes
Models
PEAD-RP35JAPEAD-RP35JALPEAD-RP50JAPEAD-RP50JALPEAD-RP60JAPEAD-RP60JALPEAD-RP71JAPEAD-RP71JALPEAD-RP100JAPEAD-RP100JALPEAD-RP125JAPEAD-RP125JALPEAD-RP140JAPEAD-RP140JAL
Source: Mitsubishi Electric PEAD-RP35-140JA(L) Service Manual, 10-8 DC fan motor check, p.39. Written in our own words as a summary; always check the original manual.
General guidance for qualified technicians. The manufacturer's installation and service manual and local codes always take priority. Aurora Star Tech is not affiliated with, endorsed by or sponsored by any equipment manufacturer; brand and model names are used only to identify equipment and belong to their owners.