SolarpunkHomes
Sign inCall us · +44 7510 081687
Heat pumps
Heat pumps · Error codes · Trianco
E08Trianco

E08 on a Trianco heat pump: Communication Fault

Short answer

On a Trianco heat pump, E08 means: Communication Fault. 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 · 5 sources

What it means

On the Activair Commercial R290 50kW (FG9550)

The manual says: Communication Fault.

Part involved: controller/PCB communication.

Likely causes:

  • Abnormal communication between wire controller and the main board.

On the Activair High Temperature R290 (5/9/15/22kW)

The manual says: Communication failure between PCB and display.

Part involved: controller/PCB communication.

Likely causes:

  • Communication error between PCB and DISPLAY.

On the Activair R290 Indoor (3.2kW wall hung / 5kW floor standing)

The manual says: Communication Fault.

Part involved: controller/PCB communication.

Likely causes:

  • Communication failure between wire controller and mainboard.

On the Activair R410A indoor wall hung 3kW (S300)

The manual says: Communication failure (wired remote control with master signal failure).

Part involved: controller/PCB communication.

On the Activair Pro (AI) R290 6/12/17kW

The manual says: Communication Fault.

Part involved: controller/PCB communication.

Likely causes:

  • Communication failure between wire controller and mainboard.

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

On the Activair Commercial R290 50kW (FG9550)

  • Inspect whether the wire controller, the main board and the connection there are reliable.

Who to ask for: heat pump controls / electrical.

Certification: Electrical competence (Part P / qualified electrician) for work inside control panels.

On the Activair High Temperature R290 (5/9/15/22kW)

  • Check cable connection of PCB and DISPLAY.
  • Check the software version of PCB and DISPLAY.

Who to ask for: heat pump controls / electrical.

Certification: Electrical competence (Part P / qualified electrician) for work inside control panels.

On the Activair R290 Indoor (3.2kW wall hung / 5kW floor standing)

  • Check the wire connection between remote wire controller and main board.

Who to ask for: heat pump controls / electrical.

Certification: Electrical competence (Part P / qualified electrician) for work inside control panels.

On the Activair R410A indoor wall hung 3kW (S300)

  • Check the connection line between the wired remote control and motherboard.

Who to ask for: heat pump controls / electrical.

Certification: Electrical competence (Part P / qualified electrician) for work inside control panels.

On the Activair Pro (AI) R290 6/12/17kW

  • Check the wire connection between remote wire controller and main board.

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

A code explains what the controller detected, not a confirmed root cause.

Reviewed: 23 September 2026