Mitsubishi Error Code P4: Drain Sensor Error
Warning: Your Mitsubishi HVAC system has detected a potential water leak and has shut down to prevent damage. Call a professional for repair.
How to Fix Mitsubishi Code P4
- Check for and clear any clogs in the condensate drain line
- Inspect the drain pan for signs of water buildup
- If water is present, call a professional HVAC technician
How to Reset Mitsubishi Code P4
- 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.
What does P4 mean?
The P4 error code on your Mitsubishi HVAC system indicates a fault with the drain sensor. This sensor is responsible for detecting water buildup in the condensate pan. When it malfunctions, it can cause your system to shut down to prevent water damage. The most common causes for this error are a clogged drain line or a faulty sensor.
Affected Models
- Puff (P-Series)
- Diamond (PJ)
- City Multi (Y)
- MSZ-AP Series
- MUZ-FE Series
- MSZ
- PUMY
- MSZ-FD
- MSZ-FT
- MSZ-FY
- MSZ-FS
- MSZ-GE
- MSZ-AS
- P-Series
- M-Series
- MSZ-LV
- MSZ-FS/FD Series
- MSZ-AP5 Series
- MSZ Series
- M-Series
- P-Series
- Diamond Series
- MSZ-FS
- City Multi (VRF)
- Ducted Systems
- MSZ-AS
- Diamond Plus
- MSZ-FE
- MSZ-AP
- PUMA
Replacement Parts
| Part | OEM Number | Est. Cost |
|---|---|---|
| Drain Sensor | 53015-24000 | — |
| Condensate Drain Line | — | — |
Related Codes on Same Models
| Code | Description | Severity |
|---|---|---|
| 1 | Indoor/Outdoor Mismatch | Warning |
| 2 | Power Supply Phase Error | Warning |
| 3 | Communication Error | Warning |
| 4 | Inverter Error | Warning |
| 5 | Outdoor Thermistor Open/Short | Warning |
| 6 | Indoor Freeze/Overheat | Warning |
| 7 | Outdoor Freeze/Overheat | Warning |
| E6 | Indoor/Outdoor Communication Error | Warning |
| E9 | Indoor/Outdoor Communication Fault | Warning |
| P1 | Intake Sensor Error | Warning |