BoilerFaultCodesYour boiler is struggling to spark or maintain a flame because the high-voltage internal ignition cable has developed a fault.
Book a Gas Safe engineer within 24–48 hours. Your boiler may be unsafe or could break down completely if left.
Technical description: HT Lead
What causes this fault?
This fault occurs when the high-voltage cable that creates the spark becomes degraded or develops a hairline crack in its insulation. When this happens, the electrical current leaks away before it can reach the burner, meaning the boiler cannot ignite the gas safely. The most common reason is simple wear and tear from the extreme heat inside the boiler casing over several years.
Engineer required
This fault requires a Gas Safe registered engineer. Do not attempt gas-related repairs yourself.
Find a Gas Safe engineer
Search the official register for a qualified engineer in your area.
Gas Safe Register →Protect yourself from future repair bills
A boiler cover plan would cover faults like E83476 — no call-out fees, no surprises.
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