BoilerFaultCodesTechnical description
Storage vessel thermistor/wiring fault
What causes this fault?
This fault occurs when the sensor responsible for monitoring the temperature inside the boiler's internal hot water storage tank fails or loses its connection. The most common reason is that the sensor has physically degraded over time or the electrical wiring has become loose or corroded, preventing the control board from knowing if the water is hot or cold.
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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