Heat pumps · Error codes · ELCO
d0ELCO · AEROTOP L (054/061/065/079/088) R32 commercial air-to-water
d0 on an ELCO AEROTOP L R32 commercial air-to-water: Gate error (d0 and address displayed alternately every 10 s)
Short answer
On an ELCO heat pump, d0 means: Gate error (d0 and address displayed alternately every 10 s). 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: Gate error (d0 and address displayed alternately every 10 s).
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
- Check the heat pump isolator and supply breakers are on (do not open any panel).
- Note the error code shown and give it to your installer / service engineer.
What the engineer will check
- Check communication wiring between boards/units and addressing.
Who to ask for: heat pump controls.
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