Grant Aerona R32 fault A5

Abnormal revolution of compressor

Heat pump

What it means

Abnormal compressor revolution detected, potentially caused by overload, voltage drop, blown fuse, clogged water circuit, or compressor/PCB fault.

Likely causes

  1. Blockage of air inlet & outlet
  2. Excess refrigerant gas
  3. Drop of power voltage
  4. Blown Fuse CF6
  5. Clogged pump/water circuit
  6. Momentary power stop (lightning)
  7. Compressor or Main PCB fault
  8. Thermal store set point reached (normal stop)
  9. Outgoing water temperature reaching protection limit (abnormal/protective stop)

Where to start

  1. Check the place of installation (blockage of air inlet & outlet)
  2. Check the excess gas
  3. Check the power voltage (230V) during operation

The full answer, free

  • 19 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 56), 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 R32. Check the model on the data plate before you order parts.

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