High Lockout
H2 on Ideal HP290

Your heat pump has stopped working because a sensor that monitors the temperature of the internal heating fluid has developed a fault.

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

Plate Heat Exchanger Outlet Refrigerant Thermistor (T2) Error

What causes this fault?

This fault occurs when the system's internal control board loses the ability to read the temperature from a specific sensor on the heat exchanger. This usually happens because the sensor itself has failed due to wear and tear, or because the electrical wiring connecting it to the brain of the unit 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

H1View →H3View →

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