Heat pumps · Error codes · ELCO
FbELCO · AEROTOP L (054/061/065/079/088) R32 commercial air-to-water
Fb on an ELCO AEROTOP L R32 commercial air-to-water: Pressure sensor fault
Short answer
On an ELCO heat pump, Fb means: Pressure sensor fault. 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: Pressure sensor fault.
When it shows: Detected from 15 min after start-up if pressure < 0.3 MPa; not during defrost.
Is it safe?
| 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
- Note the error code shown and give it to your installer / service engineer.
What the engineer will check
- Check probe wiring/connector and resistance; replace probe.
Who to ask for: heat pump / electrical.
Sources
- AEROTOP L Air-Water Heat Pump - User Manual for Authorized Service Technicians (no. 420011134100) ↗ · 420011134100 · page 59 · Reviewed 23 September 2026
A code explains what the controller detected, not a confirmed root cause.
Reviewed: 23 September 2026