Heat pumps · Error codes · Thermia
refr-1-sensorThermia · Atec
refr-1-sensor on a Thermia Atec: Sensor fault alternatively cable fault. Refrigerant sensor 1
Short answer
On a Thermia heat pump, refr-1-sensor means: Sensor fault alternatively cable fault. Refrigerant sensor 1. The heat pump keeps running with some functions stopped. An engineer is needed to fix the cause.
Reviewed 23 September 2026 · 1 source
What it means
The manual says: Sensor fault alternatively cable fault. Refrigerant sensor 1.
Part involved: refrigerant sensor 1.
Likely causes:
- Sensor or cable fault. (causes from the equivalent Danfoss DHP-AQ service instructions VMGFJ202).
Is it safe?
| Does the heat pump stop? | Partly |
|---|---|
| Severity | Fault — clears by itself when the condition goes |
| Engineer needed? | Yes |
The heat pump keeps running with some functions stopped.
What you can check
- Note the exact alarm text. Acknowledge once (operating mode OFF then back); if it remains, contact a service technician (user manual 086L0130 p.25).
What the engineer will check
- Disconnect the sensor and measure resistance with and without its cable against the ohm table in 'Measurement points' (section 3.3); replace the sensor if out of tolerance, otherwise the cable.
Who to ask for: heat pump engineer.
What you might notice
Sources
- Service Instructions Atec (VIIFM102) - silo.tips copy ↗ · VIIFM102 · page p.10 · Reviewed 23 September 2026
A code explains what the controller detected, not a confirmed root cause.
Reviewed: 23 September 2026