ODU1-12F on an Atlantic heat pump: Compressor temperature protection (permanent stoppage)
Short answer
On an Atlantic heat pump, ODU1-12F means: Compressor temperature protection (permanent stoppage). The heat pump stops until the fault clears or is reset. An engineer is needed to fix the cause. The wording differs by model range — each is shown below.
Reviewed 23 September 2026 · 2 sources
What it means
On the Alféa Excellia / Excellia Duo (R410A split, 11-16, pre-A.I.)
The manual says: Compressor temperature protection (permanent stoppage).
Likely causes:
- Refrigerant circuit protection (pressure/temperature out of range).
On the Alféa Hybrid Duo (heat pump + integrated fuel-oil boiler)
The manual says: IPM board faulty.
Likely causes:
- Power supply abnormality or outdoor/indoor PCB, inverter or IPM fault.
Is it safe?
On the Alféa Excellia / Excellia Duo (R410A split, 11-16, pre-A.I.)
| Does the heat pump stop? | Yes |
|---|---|
| Severity | Safety lockout |
| Engineer needed? | Yes |
The heat pump stops until the fault clears or is reset.
On the Alféa Hybrid Duo (heat pump + integrated fuel-oil boiler)
| Does the heat pump stop? | Yes |
|---|---|
| Severity | Fault — clears by itself when the condition goes |
| Engineer needed? | Yes |
The heat pump stops until the fault clears or is reset.
What you can check
On the Alféa Excellia / Excellia Duo (R410A split, 11-16, pre-A.I.)
- Check the outdoor unit is not blocked by leaves, debris or snow.
- Note the error number/LED pattern shown and give it to your installer.
On the Alféa Hybrid Duo (heat pump + integrated fuel-oil boiler)
- Check the heat pump isolator and consumer-unit breakers are on (do not open any casing).
- Note the error number/LED pattern shown and give it to your installer.
- If breakers trip repeatedly, leave the unit off and call an engineer.
What the engineer will check
On the Alféa Excellia / Excellia Duo (R410A split, 11-16, pre-A.I.)
- Check refrigerant charge and leaks, expansion valve, pressure sensor/switch and airflow.
- Check water flow through the plate heat exchanger.
Who to ask for: refrigeration (F-gas).
Certification: F-gas certification for refrigerant work.
On the Alféa Hybrid Duo (heat pump + integrated fuel-oil boiler)
- Check supply voltage, PCB, inverter/IPM/PFC components and connectors.
Who to ask for: electrical / heat pump.
Certification: Qualified electrician / heat pump engineer.
Sources
- alféa excellia duo Maintenance Document (U0546279_1738_EN_16) ↗ · U0546279_1738_EN_16 · page 72 · Reviewed 23 September 2026
- alféa hybrid duo Installation and commissioning instructions (doc 1440-13) ↗ · 1440-13 · page 66 · Reviewed 23 September 2026
A code explains what the controller detected, not a confirmed root cause.
Reviewed: 23 September 2026