Heat pumps · Error codes · Lämpöässä
resistor-full-powerLämpöässä · Vsi / Vmi (ÄssäControl) GSHP with 430 l tank
resistor-full-power on a Lämpöässä Vsi / Vmi GSHP with 430 l tank: Electric heater has run at full power (regulator alarm)
Short answer
On a Lämpöässä heat pump, resistor-full-power means: Electric heater has run at full power (regulator alarm). The heat pump keeps running. An engineer is needed to fix the cause.
Reviewed 23 September 2026 · 1 source
What it means
The manual says: Electric heater has run at full power (regulator alarm).
Likely causes:
- Electric heater has run at full power (regulator alarm).
Is it safe?
| Does the heat pump stop? | No |
|---|---|
| Severity | Information only |
| Engineer needed? | Yes |
The heat pump keeps running.
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
- No action required during commissioning pre-heating (manual).
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