Midea R32 M thermal Arctic Mono fault PP

What it means

Error code 38. Triggered when water side heat exchanger inlet temperature exceeds outlet temperature during heating mode, detected by user interface and hydronic system main PCB.

Likely causes

1. Reverse water flow
2. Water flow direction fault
3. Insufficient refrigerant caused by refrigerant leakage
4. Low pressure side blocked by crushed or bent pipe, blocked EXV, or dirty filter
5. Poor air side heat exchanger heat exchange in heating or DHW mode
6. Insufficient water flow rate in cooling mode

Where to start

1. Step 1: Check if water flow switch connection (CN8) on hydronic system main PCB is loose
2. Step 2: If connection is fine, check the water flow via wired controller spot check flow after water pump is switched on
3. Step 4: If water circuit is fine, determine if water flow switch is damaged using multimeter ohm range test