High Lockout
Tw_Out on Ideal HP290

Your heat pump has stopped working because a sensor that measures the temperature of the water leaving the outdoor unit has failed or is disconnected.

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 control system loses the signal from the sensor that monitors the temperature of the water exiting the outdoor unit. The most common reason is that the sensor has developed an internal electrical failure, or its connecting wires have become damaged or corroded due to exposure to the elements. Without this data, the system cannot safely regulate heat production and shuts down to prevent damage.

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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