low-temperature-collector-circuit-out-e2x-t11 on an IVT Greenline HE: Warning/alarm is given if the temperature of the collector circuit out is too low. First, a warning is given. If the warning appears several times during a certain time period, the warning transforms into a category A alarm. For settings of T11: (ÆChapter 16.9 )
Short answer
On an IVT heat pump, low-temperature-collector-circuit-out-e2x-t11 means: Warning/alarm is given if the temperature of the collector circuit out is too low. First, a warning is given. If the warning appears several times during a certain time period, the warning transforms into a category A alarm. For settings of T11: (ÆChapter 16.9 ). 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: Warning/alarm is given if the temperature of the collector circuit out is too low. First, a warning is given. If the warning appears several times during a certain time period, the warning transforms into a category A alarm. For settings of T11: (ÆChapter 16.9 ).
Part involved: E2x.T11.
When it shows: Warning/alarm is given if the temperature of the collector circuit out is too low. First, a warning is given. If the warning appears several times during a certain time period, the warning transforms into a category A alarm. For settings of T11: (ÆChapter 16.9 ).
Is it safe?
| Does the heat pump stop? | Partly |
|---|---|
| Severity | Warning |
| Engineer needed? | Yes |
The heat pump keeps running with some functions stopped.
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 alarm remains after acknowledgement. Acknowledge once on the control panel; if the alarm returns, contact the installer. 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
- Investigate per the installer guide alarm description and operating data.
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.67; 6 720 643 409 p.82; 6 720 643 415 p.27; 6 720 643 415 p.34 · Reviewed 23 September 2026
A code explains what the controller detected, not a confirmed root cause.
Reviewed: 23 September 2026