Grant Aerona R32 fault F5
Main PCB communication error
Heat pumpWhat it means
Communication error between main PCB and controller PCB, caused by incorrect wiring or loose connections.
Likely causes
- Incorrect main PCB wiring
- Faulty main PCB
- Faulty controller PCB
Where to start
- Confirm pre-plumbed cylinder wiring already completed if applicable
- Check shielding used if cable run exceeds 30m for wiring centre to heat pump cable
The full answer, free
- The readings and component tests from the manual
- How to put it right, step by step
- The manual page for this fault (page 58), 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.
Other Grant Aerona R32 fault codes
- 740Remote controller communication error
- A0DC voltage error
- A1Discharge temperature error
- A2Protective action against excess current DC current detection
- A4Protective action against excess current AC current detection
- A5Abnormal revolution of compressor
- A6Suction temperature sensor error
- A7Auto defrost temp sensor error
- A8Discharge temp. sensor error
- C1Upper fan motor error (HPID13R32 & HPID17R32)
- C2Outdoor temp. sensor error
- C3Lower fan motor error (HPID13R32 & HPID17R32) / fan motor error (HPID6R32 & HPID10R32)
- C4Rise of temperature (above 110°C) of main PCB
- C7Controller PCB serial error
- C8Main PCB error
- E4Outgoing water temp. sensor error
- E5Return water temp. sensor error
- E8Remote controller communication error
- L0EEPROM error
- L1DHW temperature sensor error
- L2Outdoor temperature sensor error
- L3Thermal store temperature sensor error
- L4Mix water temperature sensor error
- P1Pump error