BoilerFaultCodesYour boiler has detected an electrical fault with one of its internal temperature sensors, which is preventing it from monitoring heat levels safely and will likely stop it from working.
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: Short circuit on the sensor lead (T1).
What causes this fault?
This fault occurs when the boiler's main control board loses its ability to accurately measure the water temperature because the sensor's electrical circuit has been broken or crossed. The most common reason is that the internal sensor has failed due to age, or the wiring connecting it has become damaged or loose, preventing the boiler from operating safely.
Engineer required
This fault requires a Gas Safe registered engineer. Do not attempt gas-related repairs yourself.
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A boiler cover plan would cover faults like Fault 40 / 101 — 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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