Heat pumps · Error codes · Fujitsu
105Fujitsu · WATERSTAGE split (Comfort, High Power, Super High Power)
105 on a Fujitsu WATERSTAGE split: Maintenance message
Short answer
On a Fujitsu heat pump, 105 means: Maintenance message. The heat pump keeps running with some functions stopped.
Reviewed 23 September 2026 · 1 source
What it means
The manual says: Maintenance message.
Part involved: hydraulic unit controller.
Likely causes:
- Maintenance interval reached (e.g. 17: heat pump maintenance interval; 8: too many compressor starts).
Is it safe?
| Does the heat pump stop? | Partly |
|---|---|
| Severity | Information only |
| Engineer needed? | No |
The heat pump keeps running with some functions stopped.
Resetting itself: no.
Manual reset: no.
What you can check
- Note the error number shown after pressing the Info (i) key on the Waterstage user interface. Check the heat pump breakers/isolators are on. The user manual RESET key/'Reset HP' is for installers ('do not use during normal operation') - contact your installer if the fault remains.
What the engineer will check
- Carry out maintenance; reset via service menu 7070-7073.
Who to ask for: Heat pump / refrigeration engineer (manufacturer-trained).
Certification: F-gas certification for refrigerant-circuit work; electrical competence (Part P/18th Edition) for PCB/wiring.
What you might notice
Sources
- Maintenance Document - Air to Water Heat Pump Split single service and integrated DHW type (Super High Power) ↗ · 2105_EN_1 · page SHP SM p.5; DTM p.110-111 · Reviewed 23 September 2026
A code explains what the controller detected, not a confirmed root cause.
Reviewed: 23 September 2026