Mitsubishi Error Code P8: Pipe temperature out of range (coil not cooling or heating) (Heat Pump)
Mitsubishi error code P8 on a heat pump means: Pipe temperature out of range (coil not cooling or heating). It is also called Mitsubishi diagnostic code P8.
Homeowner? What Mitsubishi code P8 means for you
Call a technician Your heat pump is reporting: Pipe temperature out of range (coil not cooling or heating). The heat pump has locked out or cannot run properly. One reset is fine; if the code comes back, it needs a licensed technician to find the cause.
Safe things you can check yourself
- Check the thermostat: right mode (Heat or Cool), set a few degrees past room temperature, and fresh batteries if it uses them.
- Check both breakers and the outdoor disconnect box beside the outdoor unit; all should be ON.
- Look at the air filter. If it is grey and clogged, replace it; a blocked filter causes many shutdowns.
- In winter, keep snow and ice off and away from the outdoor unit. A short defrost cycle with steam is normal.
- Try one reset: turn the power off for 30 seconds, then back on. If the code comes back, stop resetting and call a technician.
Call (647) 657-2977Book a service call
Licensed technicians serving Vaughan, Toronto and the GTA.
What does Mitsubishi error code P8 mean?
The coil temperature does not move far enough from room temperature: in cooling the coil must be at least 3°C below the return air, in heating at least 3°C above. It takes at least 9 minutes (cooling) or 27 minutes (heating) to detect. Not checked in dry mode or during defrost.
Applies to: PEAD-RP35/50/60/71/100/125/140JA and JA(L) ducted indoor units (220-240 V models)
Common causes of Mitsubishi code P8
- Low refrigerant charge
- Pipe sensor holder loose on the pipe
- Refrigerant circuit fault
A technician checks these and 4 other possible causes on site before replacing any part.
Mitsubishi models that use code P8
PEAD-RP35JAPEAD-RP35JALPEAD-RP50JAPEAD-RP50JALPEAD-RP60JAPEAD-RP60JALPEAD-RP71JAPEAD-RP71JALPEAD-RP100JAPEAD-RP100JALPEAD-RP125JAPEAD-RP125JALPEAD-RP140JAPEAD-RP140JAL
Other Mitsubishi Heat Pump codes
All Mitsubishi Heat Pump error codes →
Mitsubishi code P8: homeowner questions
What does Mitsubishi code P8 mean?
Pipe temperature out of range (coil not cooling or heating). The coil temperature does not move far enough from room temperature: in cooling the coil must be at least 3°C below the return air, in heating at least 3°C above. It takes at least 9 minutes (cooling) or 27 minutes (heating) to detect.…
Is it safe to keep using my heat pump with code P8?
It depends on the cause. The heat pump has locked out or cannot run properly. One reset is fine; if the code comes back, it needs a licensed technician to find the cause.
Can I reset Mitsubishi code P8 myself?
You can try one reset (power off for 30 seconds, then on). If Mitsubishi code P8 comes back, the cause is still there and a licensed technician should check it.
Who can fix Mitsubishi code P8 near me?
Aurora Star Tech Inc. repairs Mitsubishi heat pumps in Vaughan, Toronto and across the GTA. Call (647) 657-2977 or book a service call online.
Homeowner help: AC Running But Not Cooling: What to Check · Heat Pump Not Heating or Blowing Cold Air
Troubleshooting guides
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Source: Mitsubishi Electric PEAD-RP35-140JA(L) Service Manual, 10-3 Self-diagnosis action table, p.32. 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.