BoilerFaultCodesTechnical description
Burner does not start. Cylinder sensor fault (short circuit or lead break).
What causes this fault?
This fault occurs when the boiler loses its electrical connection to the probe that monitors your hot water tank’s temperature. The most common reason is that the internal wiring has become damaged, or the sensor itself has suffered an electrical failure, meaning the boiler can no longer tell if your water is hot or cold. As a safety precaution, the system stops the burner from firing to prevent the water from overheating.
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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