tripped-low-pressure-switch-e2x-rlp on an IVT Greenline HE: The compressor is stopped because of too low pressure in the refrigerant circuit. Activated on open contact on the low pressure switch. The alarm is delayed with 150s after compressor start or alternation between hot water and heating production
Short answer
On an IVT heat pump, tripped-low-pressure-switch-e2x-rlp means: The compressor is stopped because of too low pressure in the refrigerant circuit. Activated on open contact on the low pressure switch. The alarm is delayed with 150s after compressor start or alternation between hot water and heating production. 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: The compressor is stopped because of too low pressure in the refrigerant circuit. Activated on open contact on the low pressure switch. The alarm is delayed with 150s after compressor start or alternation between hot water and heating production.
Part involved: E2x.RLP.
When it shows: The compressor is stopped because of too low pressure in the refrigerant circuit. Activated on open contact on the low pressure switch. The alarm is delayed with 150s after compressor start or alternation between hot water and heating production.
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: 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. Check that the air ways to and from the heat pump are not obstructed. Contact the dealer if the alarm remains after acknowledgement. Acknowledge once on the control panel; if the alarm returns, contact the installer.
What the engineer will check
- Check refrigerant circuit pressures, superheat and charge; check brine/heating flows, particle filters and pressure switch.
Who to ask for: heat pump engineer.
Certification: F-Gas category I certificate (refrigerant circuit work).
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.26 · Reviewed 23 September 2026
A code explains what the controller detected, not a confirmed root cause.
Reviewed: 23 September 2026