SENSOR-GTX on an IVT Greenline HT Plus: Sensor fault: any connected temperature sensor (e.g. GT1 return radiator) gives an alarm when defective; display shows the sensor designation
Short answer
On an IVT heat pump, SENSOR-GTX means: Sensor fault: any connected temperature sensor (e.g. GT1 return radiator) gives an alarm when defective; display shows the sensor designation. 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: any connected temperature sensor (e.g. GT1 return radiator) gives an alarm when defective; display shows the sensor designation.
Part involved: temperature sensors GT1...GT11.
Likely causes:
- Temporary error; short circuit or broken sensor cable; defective sensor or incorrect connection.
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.
Resetting itself: Yes.
What you can check
- Note which sensor (GTx) is shown and wait to see if it clears; if not, contact your dealer.
What the engineer will check
- Switch off power, disconnect sensor and check resistance against the sensor table (e.g. 15.28 kOhm at 0°C, 5.87 kOhm at 20°C).
Who to ask for: heat pump engineer.
What you might notice
Sources
- Greenline HT Plus C and E Guide to installation, commissioning and maintenance (Art. no 290410-29, v1.1) ↗ · 290410-29 v1.1 · page p.39 · Reviewed 23 September 2026
A code explains what the controller detected, not a confirmed root cause.
Reviewed: 23 September 2026