High Lockout
HA on Ideal HP290

Your heat pump has stopped because a sensor that measures the temperature of the water leaving the outdoor unit is giving an incorrect reading.

Reviewed by the BoilerFaultCodes Editorial Team · Last reviewed

Call an engineer soon

Book a Gas Safe engineer within 24 to 48 hours. Your boiler may be unsafe or could break down completely if left.

Technical description

Outdoor Unit, Flow Thermistor (Tw_out) Error

What causes this fault?

This fault occurs when the heat pump’s internal computer receives an impossible or missing temperature reading from the water outlet pipe. The most common reason is that the sensor has physically failed due to wear and tear, or the electrical connection between the sensor and the main control board has become loose or damaged.

Engineer required

This is a high severity fault. Stop using the boiler and call a Gas Safe registered engineer. Do not attempt gas-related repairs yourself.

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Related fault codes

H9View →H3View →

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