Heat pumps · Error codes · Atlantic
IF-11Atlantic
IF-11 on an Atlantic heat pump: Communication error between hydraulic unit and outdoor unit
Short answer
On an Atlantic heat pump, IF-11 means: Communication error between hydraulic unit and outdoor unit. The heat pump stops until the fault clears or is reset. An engineer is needed to fix the cause.
Reviewed 23 September 2026 · 2 sources
What it means
The manual says: Communication error between hydraulic unit and outdoor unit.
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
- alféa excellia duo Maintenance Document (U0546279_1738_EN_16) ↗ · U0546279_1738_EN_16 · page 69 · Reviewed 23 September 2026
- alféa extensa + Installation and operating manual (doc 1734-10, 1734-EN) ↗ · 1734-10 · page 75 · Reviewed 23 September 2026
A code explains what the controller detected, not a confirmed root cause.
Reviewed: 23 September 2026