Technical description
Interrupt.: DHW outlet sensor on ext. contr. - UK link box is connected without the domestic hot water temperature sensor being bridged
What causes this fault?
This fault occurs when the boiler’s internal control system expects to see a hot water sensor connected but cannot find a signal. It is usually caused by a loose connection in the wiring link box or a faulty temperature sensor that has stopped communicating with the main circuit board. Without this data, the boiler shuts down as a safety precaution because it cannot accurately monitor the temperature of the water being sent to your taps.
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.