P8 - The pipe temperature sensing circuit is reporting an error.
Mitsubishi Electric lists P8 as a pipe temperature error in the PEA installation manual. That indicates the indoor unit is seeing an abnormal pipe-temperature reading or related sensing fault.
Applies to the PEA-M100-160HAA installation-manual family; interpretation should be confirmed against the installed indoor and outdoor match.
Severity
High
Display
Shown as check code P8 on the remote controller. In the self-check table, eight beeps/flashes map to P8.
Support first?
Often not
Models in range
PEA-M100HAA, PEA-M125HAA, PEA-M140HAA
What to do first
Start with these checks
- 1Turn the unit off and restart it once after a short wait.
- 2Check that airflow is not heavily restricted by blocked filters or grilles.
- 3Book service if the code returns.
Likely causes
What usually sits behind this code
Pipe temperature thermistor fault
Sensor wiring or connector issue
Abnormal refrigerant temperature conditions
Contact support
Contact customer support if any of these apply
- !P8 stays active after restart
- !Heating or cooling output is poor with the code present
- !The system cycles into fault repeatedly
- - The official table labels P8 as 'Pipe temperature error'.
- - The PEA manual notes that some sensor-related codes can involve multiple sensors per unit.
More ranges
More Mitsubishi Electric air-conditioner ranges
Source notes
Source and scope
Source: Mitsubishi Electric Australia installation manual
The PEA-M100-160HAA installation manual lists P8 in the check-code table as 'Pipe temperature error'.
Last reviewed: 2026-04-19
The official code identifies the sensing category, but a qualified technician is still needed to distinguish sensor failure from a broader system condition.