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Heat pumps · Error codes · Alpha Heating Innovation
A475Alpha Heating Innovation · Alpha Hydro 5/8/12/16 R32 monobloc (with Pre-Plumb 200)

A475 on an Alpha Heating Innovation Alpha Hydro 5/8/12/16 R32 monobloc: Error of outdoor unit fan no.2 (where present)

Short answer

On an Alpha Heating Innovation heat pump, A475 means: Error of outdoor unit fan no.2 (where present). 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: Error of outdoor unit fan no.2 (where present).

Part involved: outdoor unit.

Likely causes:

  • Check wiring, fan power and board fuses.

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 code and any text shown on the display/controller.
  • Check the heat pump isolator and consumer-unit breaker are on.
  • Check the outdoor unit is not blocked by debris, snow or leaves.

What the engineer will check

  • Check wiring, fan power and board fuses.

Who to ask for: heat pump engineer.

Sources

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

Reviewed: 23 September 2026