high-temperature-difference-collector-circuit-e2x on an IVT Greenline HE: The warning is activated when the difference between sensor E2x.T10 and E2x.T11 exceeds 6K. 30 min after compressor start and change of production mode, the temperature difference is measured and if it is too big, the warning is given after a delay of 15 min. The warning is not given when the compressor is inactive
Short answer
On an IVT heat pump, high-temperature-difference-collector-circuit-e2x means: The warning is activated when the difference between sensor E2x.T10 and E2x.T11 exceeds 6K. 30 min after compressor start and change of production mode, the temperature difference is measured and if it is too big, the warning is given after a delay of 15 min. The warning is not given when the compressor is inactive. 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: The warning is activated when the difference between sensor E2x.T10 and E2x.T11 exceeds 6K. 30 min after compressor start and change of production mode, the temperature difference is measured and if it is too big, the warning is given after a delay of 15 min. The warning is not given when the compressor is inactive.
Part involved: E2x.
When it shows: The warning is activated when the difference between sensor E2x.T10 and E2x.T11 exceeds 6K. 30 min after compressor start and change of production mode, the temperature difference is measured and if it is too big, the warning is given after a delay of 15 min. The warning is not given when the compressor is inactive.
Is it safe?
| Does the heat pump stop? | No |
|---|---|
| Severity | Warning |
| Engineer needed? | Yes |
The heat pump keeps running.
Manual reset: Acknowledge on control panel.
What you can check
- Note the full alarm text including the component designation (e.g. E21.T6) - IVT asks for it when you contact the dealer. Contact the dealer if the warning remains after acknowledgement. Look at the brine expansion tank: the fluid level should be visible (user guide check). Do not refill or open the ground-loop circuit yourself - call the installer.
What the engineer will check
- Check and clean particle filter(s) (user guide lists this as a user action; recorded as engineer check per project safety policy).
Who to ask for: heat pump engineer.
What you might notice
Sources
- Installer Guide Greenline HE C6-C11 E6-E11 1x230V (6 720 802 419 (2012/06) en) ↗ · 6 720 802 419 (2012/06) · page 6 720 802 419 p.70; 6 720 643 409 p.88; 6 720 643 415 p.32 · Reviewed 23 September 2026
A code explains what the controller detected, not a confirmed root cause.
Reviewed: 23 September 2026