Grant Aerona R32 fault 740
Remote controller communication error
Heat pumpWhat it means
Communication error between remote controller and controller PCB, caused by incorrect wiring, DIP switch setting, or loose connections.
Likely causes
- Incorrect remote controller wiring or DIP SW setting
- Faulty remote controller
- Faulty controller PCB
Where to start
- Check rear side of remote controller
- 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
- 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
- F5Main PCB communication error
- L0EEPROM error
- L1DHW temperature sensor error
- L2Outdoor temperature sensor error
- L3Thermal store temperature sensor error
- L4Mix water temperature sensor error
- P1Pump error