Heat pumps · Error codes · Trianco
02Trianco · Activair (first generation) S300/S500/S800/S1200/S1300/S1800
02 on a Trianco Activair S300/S500/S800/S1200/S1300/S1800: Compressor sensor cutout activated
Short answer
On a Trianco heat pump, 02 means: Compressor sensor cutout activated. 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 sensor cutout activated.
Part involved: temperature sensor/thermistor.
Likely causes:
- Sensor disconnected.
- Short circuit.
- Faulty sensor.
Is it safe?
| Does the heat pump stop? | Yes |
|---|---|
| Engineer needed? | Yes |
The heat pump stops until the fault clears or is reset.
What you can check
- Note the exact code shown on the controller (a photo helps) and report it to your installer or the manufacturer's service line.
- Check the heat pump's supply breaker/isolator at the consumer unit is on (do not open any casing).
What the engineer will check
- Reconnect sensor to PCB.
- Check connection between sensor and appliance.
- Check sensor for correct operation.
- repair or replace as necessary.
Who to ask for: heat pump controls / electrical.
Certification: Competent heat pump engineer; electrical competence for work inside the unit.
What you might notice
Sources
- Trianco Activair Air-to-Water Air Source Heat Pump S300 & S500 - User, Installation, Commissioning & Servicing Instructions (224511) ↗ · 224511 · page 21 · Reviewed 23 September 2026
A code explains what the controller detected, not a confirmed root cause.
Reviewed: 23 September 2026