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Heat pumps · Error codes · Hisa Engineering Ltd
E09Hisa Engineering Ltd · Hisa hr290

E09 on a Hisa Engineering Ltd Hisa hr290: Wire controller communication failure

Short answer

On a Hisa Engineering Ltd heat pump, E09 means: Wire controller communication failure. The manual does not say whether the heat pump stops. An engineer is needed to fix the cause.

Reviewed 24 September 2026 · 1 source

What it means

The manual says: Wire controller communication failure.

Part involved: PCB / communication.

Likely causes:

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

Is it safe?

Does the heat pump stop?Not stated
Engineer needed?Yes

The manual does not say whether the heat pump stops.

Resetting itself: unknown.

What you can check

  • Note the code shown on the controller and the model number on the rating label before contacting your installer.
  • Check that the heat pump isolator / consumer-unit breaker is on; do not open any casing.
  • A single restart via the controller (off/on) may be tried only if the manual or your installer allows it.

What the engineer will check

  • Follow the manufacturer's troubleshooting steps for this code.
  • Check the relevant sensor/switch wiring and connectors.
  • Measure/replace the component or PCB as indicated.

Who to ask for: electrical.

What you might notice

Sources

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

Reviewed: 24 September 2026