Heat pumps · Error codes · Atlantic
370-23Atlantic · Alféa Extensa A.I. / Extensa Duo A.I. R32 (split, 3-10)
370-23 on an Atlantic Alféa Extensa A.I. / Extensa Duo A.I. R32: Combination error
Short answer
On an Atlantic heat pump, 370-23 means: Combination error. 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: Combination error.
Likely causes:
- Communication/connection fault between hydraulic unit and outdoor unit (or between boards), or incompatible combination.
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 consumer-unit breakers are on (do not open any casing).
- Note the error number/LED pattern shown and give it to your installer.
What the engineer will check
- Check interconnection cable and terminals between indoor and outdoor units.
- Check board connectors and unit combination.
Who to ask for: heat pump / electrical.
What you might notice
Sources
- Alfea Extensa A.I. R32 Installation manual (U0671217_2114_EN_11) ↗ · U0671217_2114_EN_11 · page 72 · Reviewed 23 September 2026
A code explains what the controller detected, not a confirmed root cause.
Reviewed: 23 September 2026