BoilerFaultCodesYour boiler has detected a fault with a temperature sensor and has stopped working as a safety precaution.
Book a Gas Safe engineer within 24–48 hours. Your boiler may be unsafe or could break down completely if left.
Technical description: CH flow thermistor open or short circuit
What causes this fault?
This fault occurs when the boiler's internal computer loses communication with the sensor that monitors the temperature of the water leaving the unit. The most common reason is that the sensor has physically failed due to age or internal wear, but it can also be caused by loose or damaged electrical wiring. Because the boiler no longer knows how hot the water is, it shuts down immediately to prevent the system from overheating.
Engineer required
This fault requires a Gas Safe registered engineer. Do not attempt gas-related repairs yourself.
Find a Gas Safe engineer
Search the official register for a qualified engineer in your area.
Gas Safe Register →Protect yourself from future repair bills
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