GT6 on an IVT Greenline HT Plus: Compressor temperature T6 (GT6): the working temperature of the compressor is too high
Short answer
On an IVT heat pump, GT6 means: Compressor temperature T6 (GT6): the working temperature of the compressor is too high. The heat pump stops until the fault clears or is reset. An engineer is needed to fix the cause.
Reviewed 23 September 2026 · 1 source
What it means
The manual says: Compressor temperature T6 (GT6): the working temperature of the compressor is too high.
Part involved: compressor discharge (hot gas) sensor GT6.
Likely causes:
- Compressor working temperature too high; intermittent temperature rise due to abnormal operating conditions.
Is it safe?
| Does the heat pump stop? | Yes |
|---|---|
| Severity | Fault — needs a manual reset once the cause is fixed |
| Engineer needed? | Yes |
The heat pump stops until the fault clears or is reset.
Manual reset: Ackn. button on Rego 637 control panel.
What you can check
- Press the Ackn. button on the control panel once (the manual says there is no risk in resetting an alarm; the heat pump restarts within 15 minutes if heat is needed). If the alarm returns, contact your installer.
What the engineer will check
- Check refrigerant charge/superheat, expansion valve, operating conditions, GT6 sensor.
Who to ask for: heat pump engineer.
Certification: F-Gas category I certificate (refrigerant circuit work).
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.35 · Reviewed 23 September 2026
A code explains what the controller detected, not a confirmed root cause.
Reviewed: 23 September 2026