BoilerFaultCodesYour boiler is unable to light the flame because the ignition system is faulty or damaged, leaving you without heating and hot water.
Book a Gas Safe engineer within 24–48 hours. Your boiler may be unsafe or could break down completely if left.
Technical description: Ignition Electrode & leadc/w Gasket & 2 screws
What causes this fault?
This fault occurs when the boiler's spark system fails to create the flame needed to produce heat. The most common reasons are that the ignition electrode has become worn or soot-covered over time, or the high-voltage lead connecting it to the control board has developed a fault.
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 E85739 — no call-out fees, no surprises.
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Parts for discontinued models can be hard to find and expensive. A new A-rated boiler could save you money on both repairs and energy bills.
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