L8 on a Ferroli heat pump: Speed difference > 15 Hz between the front and the back clock (P6 group)
Short answer
On a Ferroli heat pump, L8 means: Speed difference > 15 Hz between the front and the back clock (P6 group). The manual does not say whether the heat pump stops. 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 OMNIA M 3.2 monobloc R32 (4-16 kW and 18T-30T)
The manual says: Speed difference > 15 Hz between the front and the back clock (P6 group).
Likely causes:
- Check system pressure.
- Compressor phase resistance.
- U/V/W sequence inverter-compressor.
- L1/L2/L3 inverter-filter board.
- Inverter board.
On the OMNIA S 3.2 split (wall-hung hydronic unit + OMNIA UE 3.2 outdoor)
The manual says: Compressor frequency variation greater than 15 Hz per second.
Part involved: compressor drive.
Is it safe?
On the OMNIA M 3.2 monobloc R32 (4-16 kW and 18T-30T)
| Does the heat pump stop? | Not stated |
|---|---|
| Engineer needed? | Yes |
The manual does not say whether the heat pump stops.
Manual reset: Manual (13.4): reset the safety by turning the unit OFF and back ON; if unsuccessful contact your local dealer.
On the OMNIA S 3.2 split (wall-hung hydronic unit + OMNIA UE 3.2 outdoor)
| Does the heat pump stop? | Not stated |
|---|---|
| Engineer needed? | Yes |
The manual does not say whether the heat pump stops.
Manual reset: Manual (sect. 10.3): reset the safety device by turning the unit OFF and back ON; if unsuccessful contact the local dealer.
What you can check
- Check the consumer-unit breaker/isolator for the heat pump is on.
- Note the code shown on the user interface and contact the installer/Ferroli service.
- The manual says the safety can be reset by switching the unit OFF and back ON; if the code returns, do not keep resetting - call the installer.
What the engineer will check
On the OMNIA M 3.2 monobloc R32 (4-16 kW and 18T-30T)
- Check system pressure.
- Compressor phase resistance.
- U/V/W sequence inverter-compressor.
- L1/L2/L3 inverter-filter board.
- Inverter board.
Who to ask for: heat pump engineer.
Certification: Electrical competence for board/wiring work.
On the OMNIA S 3.2 split (wall-hung hydronic unit + OMNIA UE 3.2 outdoor)
Who to ask for: heat pump engineer.
Certification: Electrical competence for board/wiring work.
What you might notice
Sources
- OMNIA M 3.2 mod. 4-16 - Reversible heat pumps for outdoor installation with DC inverter compressor - installation/owner manual (IT-EN...) ↗ · Cod. 3QE47740 - Rev. 02 - 11/2023 · page 76 · Reviewed 23 September 2026
- OMNIA S 3.2 - Installation, use and maintenance manual (IT-EN-ES-PT-FR-DE-NL) ↗ · Cod. 3541V942 - Rev. 01 - 06/2026 · page 126 · Reviewed 23 September 2026
A code explains what the controller detected, not a confirmed root cause.
Reviewed: 23 September 2026