E131 on a Trianco heat pump: System 1 Refrigerant Leak Anomaly
Short answer
On a Trianco heat pump, E131 means: System 1 Refrigerant Leak Anomaly. The manual does not say whether the heat pump stops. An engineer is needed to fix the cause. The wording differs by model range — each is shown below.
Reviewed 23 September 2026 · 2 sources
What it means
On the Activair R290 Indoor (3.2kW wall hung / 5kW floor standing)
The manual says: System 1 Refrigerant Leak Anomaly.
Part involved: refrigerant leak detector.
Likely causes:
- Refrigerant Leak.
On the Activair Pro (AI) R290 6/12/17kW
The manual says: Refrigerant Leak.
Part involved: refrigerant leak detector.
Likely causes:
- Refrigerant leak detected.
Is it safe?
| Does the heat pump stop? | Not stated |
|---|---|
| Severity | Safety lockout |
| Engineer needed? | Yes |
The manual does not say whether the heat pump stops.
What you can check
On the Activair R290 Indoor (3.2kW wall hung / 5kW floor standing)
- Keep people away from the unit, ventilate the room/area and keep ignition sources (flames, sparks) away.
- Do NOT switch the heat pump off at the isolator unless instructed: the manual says the unit must stay powered so the leak-detection fan can disperse refrigerant.
- Call your installer or a R290-competent F-gas engineer urgently and report code E131.
On the Activair Pro (AI) R290 6/12/17kW
- Keep people, pets and ignition sources (flames, sparks, smoking) away from the outdoor unit.
- Call your installer or a R290-competent F-gas engineer urgently and report code E131.
What the engineer will check
On the Activair R290 Indoor (3.2kW wall hung / 5kW floor standing)
- Check for any refrigerant leakage.
Who to ask for: refrigeration (flammable refrigerant).
Certification: F-gas certified engineer with R290/flammable-refrigerant competence.
On the Activair Pro (AI) R290 6/12/17kW
- Check for leak.
Who to ask for: refrigeration (flammable refrigerant).
Certification: F-gas certified engineer with R290/flammable-refrigerant competence.
What you might notice
Sources
- Trianco Activair R290 High Temperature Indoor Air Source Heat Pump (3.2kW wall hung) - Installation Operation and Service Manual ↗ · 2026-08 · page 33 · Reviewed 23 September 2026
- Trianco Activair Pro Air Source Heat Pump (R290 6/12/17kW) - Installation Operation and Service Manual ↗ · 06/2026 · page 41 · Reviewed 23 September 2026
A code explains what the controller detected, not a confirmed root cause.
Reviewed: 23 September 2026