Midea R32 M thermal Arctic Mono fault H8

What it means

Error code 47. Pressure sensor error detected by user interface and refrigerant system main PCB.

Likely causes

1. Pressure sensor short-circuited or failed
2. Pressure sensor not connected properly or has malfunctioned
3. Refrigerant system main PCB damaged
4. Pressure sensor fault
5. Sensor wiring fault
6. Sensor resistance inconsistent with characteristics table
7. Pressure sensor failure
8. High pressure side blockage
9. Air side heat exchanger, fan or air outlet dirt/blockage
10. Water side heat exchanger, water piping, circulator pump or water flow switch dirt/blockage

Where to start

1. Measure resistance among the three terminals of the pressure sensor; if resistance is of the order of mega Ohms or infinite, the pressure sensor has failed
2. Step 1: Check high pressure sensor connection on refrigerant system main PCB for looseness - if yes, ensure sensor connected properly
3. Step 2: Measure resistance among the three terminals of the pressure sensor to check for short-circuit or failure - if failed, replace the sensor