Understand the display
Mitsubishi Ecodan error codes
The official meaning, a plain-English explanation and your next step.
P1 · Mitsubishi Electric · Ecodan
Official meaning: Room-temperature thermistor abnormality.
The controller may not be receiving a valid reading from a room-temperature sensor.
What you can check
Photograph the display and note the full indoor and outdoor model numbers. Check your model’s user instructions; leave wiring and internal sensor checks to an engineer.
Your next step
An engineer may need to check the sensor and its connections. Do not open the controller or appliance.
Every Ecodan code we hold, with its source and the checks you can safely make, is on the error-code pages.
Source
Next step
Open the P1 code page →