TradeAssistIQHome

Midea R32 M thermal Arctic Mono fault PB

Water side heat exchanger anti-freeze protection

Heat pump

What it means

Error code 31. Anti-freeze protection for water side heat exchanger detected by user interface and hydronic system main PCB.

Likely causes

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

Where to start

  1. Verify water pump operation during protection cycle
  2. Step 1: Check if water flow switch connection (CN8) on hydronic system main PCB is loose
  3. Step 2: If connection is fine, check the water flow via wired controller spot check flow after water pump is switched on

The full answer, free

  • 25 more checks in order
  • The readings and component tests from the manual
  • How to put it right, step by step
  • The manual page for this fault (page 68), right under the answer
Ask about PB freeCreate a free account

Safety: Isolate the outdoor unit and any backup heater, and give the inverter capacitors time to discharge before you open the electrics. Anything on the refrigerant circuit needs F-gas certification.

From the Midea manual for the R32 M thermal Arctic Mono. Check the model on the data plate before you order parts.

Other Midea R32 M thermal Arctic Mono fault codes