BoilerFaultCodesTechnical description
Central heating return thermistor fault
What causes this fault?
This fault occurs when the control board loses communication with the sensor that monitors the temperature of water returning to the boiler. The most common reason is that the sensor has physically failed due to wear and tear, or the electrical connection has become loose or corroded. Without this data, the boiler shuts down to prevent itself from overheating or burning fuel inefficiently.
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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