Heat pumps · Error codes · ELCO
924ELCO · Aeropur CRX (006/008/012/015) monobloc air-to-water
924 on an ELCO Aeropur CRX monobloc air-to-water: Communication error (e-BUS 2)
Short answer
On an ELCO heat pump, 924 means: Communication error (e-BUS 2). 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: Communication error (e-BUS 2).
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.
What you might notice
Sources
- AEROPUR Instruction manual (Brugsanvisning, 420010710000 - 12/2015; English section p13-26) ↗ · 420010710000 · page 23 · Reviewed 23 September 2026
A code explains what the controller detected, not a confirmed root cause.
Reviewed: 23 September 2026