E85 740 High

Potterton E85 740 Fault Code

Also written as E85740 — same fault.

The Potterton E85 740 fault code means: your boiler is failing to detect a flame, which prevents it from safely igniting and providing you with heating or hot water.. It appears on 1 Potterton model in our database.

Call an engineer soon

Book a Gas Safe engineer within 24 to 48 hours. Your boiler may be unsafe or could break down completely if left.

Technical description: Ionization Probe & lead c/w Gasket & 2 screws
Typical repair cost £150-250 (including labour)

Engineer required

This fault requires a Gas Safe registered engineer. Do not attempt gas-related repairs yourself.

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Potterton models that show the E85 740 fault code

Click a model for the full fault code list and model-specific repair notes.

Source

Potterton E85 740 fault code information on this page is sourced and cross-checked against the official Potterton service / installation manuals for each affected model.

Reviewed by the BoilerFaultCodes Editorial Team · Last reviewed 7 July 2026