Grant Aerona R290 fault E29

What it means

IPM module temperature exceeded safe operating limit.

Likely causes

1. Cables incorrectly connected
2. Refrigerant & Drive PCB is faulty
3. Outdoor air temperature (T4) below 7°C combined with low return (TA) or flow (TB) water temperature below 6°C
4. Refrigerant leak in system requiring repair
5. Refrigerant leak causing inhalation exposure
6. Refrigerant contact causing frostbite or skin/eye exposure
7. Refrigerant leak from hermetically sealed circuit
8. Improper handling during service
9. Mist of mineral oil, oil spray or vapours degrading plastic parts, causing them to come loose or leak water
10. Corrosive gases such as sulphurous acid gas or chlorine gas (e.g. near swimming pools) causing corrosion of copper pipes or soldered parts leading to refrigerant leaks
11. Machinery emitting electromagnetic waves disturbing control system causing equipment malfunction
12. Flammable gas leakage, carbon fibre or ignitable dust in air, or volatile flammables such as paint thinner or gasoline causing fire risk
13. Acidic or alkaline vapours present
14. Direct skin/eye contact with escaping refrigerant
15. Refrigerant leak exposure during service or fault

Where to start

1. Check all connections from the Refrigerant PCB (or Refrigerant & Drive PCB for the 16kW model)
2. Verify correct terminal used for each circuit function per Table 6-6
3. Confirm no 230V live wiring crosses to the low voltage side of the wiring centre split