BoilerFaultCodesYour boiler has detected a technical fault with its internal temperature sensors, which is preventing it from heating your home or water safely.
Book a Gas Safe engineer within 24–48 hours. Your boiler may be unsafe or could break down completely if left.
Technical description: E-Combi EvoE-System EVOClas HE evo combiClas he evo system
What causes this fault?
This fault occurs when the boiler's control board detects that the temperature sensors on the main pipes are sending conflicting or impossible data. It is usually caused by an electronic failure within the internal sensors themselves or a loose connection in the wiring that links them to the main computer. Because the boiler can no longer accurately monitor how hot the water is, it shuts down as a safety precaution to prevent overheating.
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 701 — 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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