BoilerFaultCodesYour boiler has detected a broken wire or a faulty connection to one of the internal temperature sensors, which is preventing it from heating properly.
Book a Gas Safe engineer within 24–48 hours. Your boiler may be unsafe or could break down completely if left.
Technical description: Temperature sensor T1 on collector group 1 faulty: Break in the sensor lead (T1).
What causes this fault?
This fault occurs when the boiler's internal computer loses communication with the main temperature sensor that monitors the heat exchanger. The most common reason is that the sensor has physically failed due to age or heat stress, or the delicate wiring connecting it to the control board has become loose or damaged.
Engineer required
This fault requires a Gas Safe registered engineer. Do not attempt gas-related repairs yourself.
Find a Gas Safe engineer
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A boiler cover plan would cover faults like Fault 40 / 102 — no call-out fees, no surprises.
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Could it be time for a new boiler?
If repair costs are adding up, a new energy-efficient boiler could be the smarter long-term choice.
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