BoilerFaultCodesYour boiler has detected a problem with a safety sensor that monitors the temperature of the exhaust gases, causing the system to lock out.
Book a Gas Safe engineer within 24–48 hours. Your boiler may be unsafe or could break down completely if left.
Technical description: Permanent fault. Flue temperature sensor short-circuited, sensor not or badly connected, bad connection or sensor fault.
What causes this fault?
This fault occurs when the boiler's safety system detects an irregular electrical signal from the sensor that monitors the heat of the exhaust gases. The most common reason is that the sensor has developed an internal electrical short or the wiring connecting it to the main control board has become loose or damaged. In some cases, it can be triggered if the heat exchanger is extremely dirty, causing exhaust temperatures to exceed safe limits.
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 E.04 – .05 — 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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