Heat pumps · Error codes · Trianco
Er09Trianco · Activair R32 (S700 / S1200 - FG 9007 / FG 9012)
Er09 on a Trianco Activair R32: Communication failure
Short answer
On a Trianco heat pump, Er09 means: Communication failure. The manual does not say whether the heat pump stops. An engineer is needed to fix the cause.
Reviewed 23 September 2026 · 1 source
What it means
The manual says: Communication failure.
Part involved: controller/PCB communication.
Likely causes:
- Communication failure between the LCD and PCB.
Is it safe?
| Does the heat pump stop? | Not stated |
|---|---|
| Engineer needed? | Yes |
The manual does not say whether the heat pump stops.
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).
- Check the controller display is lit and showing the code.
What the engineer will check
- Check the wire connection between the LCD and PCB.
- Replace LCD.
Who to ask for: heat pump controls / electrical.
Certification: Electrical competence (Part P / qualified electrician) for work inside control panels.
What you might notice
Sources
- Trianco Activair Air Source Heat Pump S700, S1200 - Installation and Service Manual (R32, FG 9007 / FG 9012) ↗ · 2022-04 issue · page 11, 20 · Reviewed 23 September 2026
A code explains what the controller detected, not a confirmed root cause.
Reviewed: 23 September 2026