TradeAssistIQHome

Grant Aerona R32 fault C4

Rise of temperature (above 110°C) of main PCB

Heat pump

What it means

Main PCB has detected a temperature rise above 110°C, potentially due to mis-installation blocking airflow or a faulty Main PCB temperature sensor.

Likely causes

  1. Blockage of air inlet & outlet (mis-installation)
  2. Main PCB sensor/board fault

Where to start

  1. Check the place of installation (blockage of air inlet & outlet)
  2. Confirm parameter 5111 and 4200 combination is valid per remarks column
  3. Check external timer is fitted if Night mode (5128) or Low tariff (5130) terminals are enabled

The full answer, free

  • 1 more check 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
Ask about C4 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 Grant manual for the Aerona R32. Check the model on the data plate before you order parts.

Other Grant Aerona R32 fault codes