Heat pumps · Error codes · ELCO
P1ELCO · AEROTOP L (054/061/065/079/088) R32 commercial air-to-water
P1 on an ELCO AEROTOP L R32 commercial air-to-water: Low pressure protection
Short answer
On an ELCO heat pump, P1 means: Low pressure protection. The heat pump stops until the fault clears or is reset. An engineer is needed to fix the cause.
Reviewed 23 September 2026 · 1 source
What it means
The manual says: Low pressure protection.
When it shows: LP switch bypassed 3 min at start-up; 10 times in 150 min requires power-off reset.
Is it safe?
| Does the heat pump stop? | Yes |
|---|---|
| Severity | Fault — needs a manual reset once the cause is fixed |
| Engineer needed? | Yes |
The heat pump stops until the fault clears or is reset.
What you can check
- Check the unit air inlet/outlet is not blocked by debris or snow.
- Note the error code shown and give it to your installer / service engineer.
What the engineer will check
- Check refrigerant pressures/charge, expansion valves, sensors, airflow and water flow.
Who to ask for: refrigeration (F-gas).
Certification: F-gas certification.
Sources
- AEROTOP L Air-Water Heat Pump - User Manual for Authorized Service Technicians (no. 420011134100) ↗ · 420011134100 · page 57 · Reviewed 23 September 2026
A code explains what the controller detected, not a confirmed root cause.
Reviewed: 23 September 2026