Heat pumps · Error codes · ELCO
PbELCO · AEROTOP L (054/061/065/079/088) R32 commercial air-to-water
Pb on an ELCO AEROTOP L R32 commercial air-to-water: Winter antifreeze protection
Short answer
On an ELCO heat pump, Pb means: Winter antifreeze protection. The heat pump keeps running.
Reviewed 23 September 2026 · 1 source
What it means
The manual says: Winter antifreeze protection.
When it shows: Status/protection function.
Is it safe?
| Does the heat pump stop? | No |
|---|---|
| Severity | Information only |
| Engineer needed? | No |
The heat pump keeps running.
What you can check
The manual lists no checks for a homeowner. Note the code and call an engineer.
What the engineer will check
The manual does not list the engineer’s checks for this code.
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