Heat pumps · Error codes · Lämpöässä
hc2-sensorLämpöässä · Vsi / Vmi (ÄssäControl) GSHP with 430 l tank
hc2-sensor on a Lämpöässä Vsi / Vmi GSHP with 430 l tank: Heating circuit 2 flow sensor fault
Short answer
On a Lämpöässä heat pump, hc2-sensor means: Heating circuit 2 flow sensor fault. The manual does not say whether the heat pump stops. An engineer is needed to fix the cause.
Reviewed 23 September 2026 · 1 source
What it means
The manual says: Heating circuit 2 flow sensor fault.
Likely causes:
- Heating circuit 2 flow sensor fault.
Is it safe?
| Does the heat pump stop? | Not stated |
|---|---|
| Engineer needed? | Yes |
The manual does not say whether the heat pump stops.
What you can check
- Note the code and any text shown on the display/controller.
- Check the heat pump isolator and consumer-unit breaker are on.
What the engineer will check
- Check sensor and wiring.
Who to ask for: heat pump engineer.
Sources
- LÄMPÖÄSSÄ Vmi 6-17 Ground Source Heat Pump - Instructions for use, installation and maintenance (7/2017) ↗ · 7/2017 · page 22 · Reviewed 23 September 2026
A code explains what the controller detected, not a confirmed root cause.
Reviewed: 23 September 2026