Grant Aerona R290 fault E29

IPM module temperature is too high

Heat pump

What it means

IPM module temperature exceeded safe operating limit.

Likely causes

  1. Cables incorrectly connected
  2. Refrigerant & Drive PCB is faulty
  3. Refrigerant leak in system requiring repair

Where to start

  1. Check all connections from the Refrigerant PCB (or Refrigerant & Drive PCB for the 16kW model)
  2. Use leak detection fluids suitable for the refrigerant, avoiding chlorine-containing detergents
  3. Avoid detergents containing chlorine as it may react with refrigerant and corrode copper pipework

The full answer, free

  • 18 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 60), right under the answer

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 Grant manual for the Aerona R290. Check the model on the data plate before you order parts.

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