Mitsubishi Error Code P8: Pipe Temp Error
Warning: Your Mitsubishi HVAC system has detected an issue with the pipe temperature, which may cause system damage if not addressed.
LED Blink Pattern
How to Fix Mitsubishi Code P8
- Step 1: Turn off your HVAC system at the thermostat and the circuit breaker to prevent further system damage.
- Step 2: Check the air filter and replace it if it's dirty. A clogged filter can cause airflow issues and overheating.
- Step 3: Call a professional HVAC technician to diagnose and repair the issue. Do not attempt to open the unit or handle refrigerant lines yourself.
How to Reset Mitsubishi Code P8
- Turn off the unit using the remote control or wall controller.
- Turn off the circuit breaker for the outdoor and indoor units. Wait 60 seconds.
- Restore power at the breaker.
- Turn the unit on with the remote control. If the error returns, the fault needs professional diagnosis.
Resetting clears the code from the display but does not fix the underlying fault. If the code returns after reset, proceed to the diagnostic steps above.
What Does Mitsubishi Error Code P8 Mean?
The P8 error on your Mitsubishi HVAC system indicates that the pipe temperature has exceeded the safe operating range. This could be due to a faulty temperature sensor or a problem with the system's refrigerant flow. If left unchecked, this issue can lead to system damage and reduced efficiency.
Common Causes
- Faulty pipe temperature sensor
- Blockage in refrigerant lines
- Defective expansion valve
- Insufficient refrigerant levels
Diagnostic Steps
| If... | Check | Expected |
|---|---|---|
| System is running | Measure the temperature of the suction and liquid lines using an infrared thermometer | Suction line should be around 40-50°F (4-10°C) and liquid line should be around 80-100°F (27-38°C) |
| System is off | Check for any visible leaks or damage to the refrigerant lines and components | No leaks or damage should be present |
Applicable Mitsubishi Models
- City Multi (VRF)(electric)
- City Multi (Y)(electric)
- Diamond (PJ)(electric)
- Diamond Plus(electric)
- Diamond Series(electric)
- Ducted Systems(electric)
- M-Series(electric)
- MSZ(electric)
- MSZ Series(electric)
- MSZ-AP(electric)
- MSZ-AP Series(electric)
- MSZ-AP5 Series(electric)
- MSZ-AS(electric)
- MSZ-FD(electric)
- MSZ-FE(electric)
- MSZ-FS(electric)
- MSZ-FS/FD Series(electric)
- MSZ-FT(electric)
- MSZ-FY(electric)
- MSZ-GE(electric)
- MSZ-LV(electric)
- MUZ-FE Series(electric)
- P-Series(electric)
- PUMA(electric)
- PUMY(electric)
- Puff (P-Series)(electric)
Replacement Parts
| Part | OEM Number | Est. Cost | Where to Buy |
|---|---|---|---|
| Pipe Temperature Sensor | 55674-00000 | — | Find Part |
| Expansion Valve | 55673-00000 | — | Find Part |
Related Codes on Same Models
Other codes that affect the same Mitsubishi model families as P8.
| Code | Description | Severity |
|---|---|---|
| 1 | Indoor/Outdoor Mismatch | Warning |
| 2 | Power Supply Phase Error | Warning |
| 4 | Inverter Error | Warning |
| 7 | Outdoor Freeze/Overheat | Warning |
| E6 | Indoor/Outdoor Communication Error | Warning |
| E9 | Indoor/Outdoor Communication Fault | Warning |
| P2 | Indoor Pipe Thermistor Error | Warning |
| P4 | Drain Sensor Error | Warning |
| P6 | Coil Freeze/Overheat Protection | Warning |
| U2 | Low Voltage/Overcurrent | Warning |