Heat pumps · Error codes · ELCO
E9ELCO · AEROTOP L (054/061/065/079/088) R32 commercial air-to-water
E9 on an ELCO AEROTOP L R32 commercial air-to-water: No water flow (manual reset) - drained system
Short answer
On an ELCO heat pump, E9 means: No water flow (manual reset) - drained system. 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: No water flow (manual reset) - drained system.
When it shows: Active 120 s after start-up; turn the power off to 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 system pressure gauge reading.
- Note the error code shown and give it to your installer / service engineer.
What the engineer will check
- Check water flow, pump, filter, probes Twi/Two positioning and air in system.
Who to ask for: heating / heat pump.
Sources
- AEROTOP L Air-Water Heat Pump - User Manual for Authorized Service Technicians (no. 420011134100) ↗ · 420011134100 · page 56 · Reviewed 23 September 2026
A code explains what the controller detected, not a confirmed root cause.
Reviewed: 23 September 2026