How much does it cost to fix Ideal error code L31?

Typical repair cost for the Ideal L31 fault is £650-£1,100 including labour.

L31 High

Ideal L31 Fault Code

Q: What does the Ideal L31 fault code mean?

Your heat pump's internal control computer has detected an electrical fault with the unit that powers the motor, preventing it from running.

The Ideal L31 fault code means: your heat pump's internal control computer has detected an electrical fault with the unit that powers the motor, preventing it from running.. It appears on 1 Ideal model in our database.

Technical description: Inverter Error

What causes the Ideal L31 fault?

This fault occurs when the internal power management system fails to supply the correct electricity to the compressor motor. It is usually triggered by a short circuit or a failed component on the inverter circuit board that prevents the heat pump from physically starting its heating cycle.

This fault can be more frequent during periods of high demand in winter, as the inverter has to work harder and generate more heat to maintain high flow temperatures.

Typical repair cost £650-£1,100 (including labour)

Engineer required

This fault requires a Gas Safe registered engineer. Do not attempt gas-related repairs yourself.

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Ideal models that show the L31 fault code

Click a model for the full fault code list and model-specific repair notes.

HP290 Repair: £650-£1,100

Source

Ideal L31 fault code information on this page is sourced and cross-checked against the official Ideal service / installation manuals for each affected model.

Reviewed by the BoilerFaultCodes Editorial Team · Last reviewed 27 April 2026