BoilerFaultCodesYour boiler has stopped working because of an internal communication failure between the main control board and the display panel.
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 'brain' and the front display panel stop talking to each other, preventing your commands from reaching the system. The most common reason is a loose connection in the internal wiring or a mechanical failure within one of the electronic circuit boards. Without this vital data link, the boiler shuts down as a safety precaution because it can no longer monitor its own settings.
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 704 — 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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