High
H58-709 on Biasi Advance Plus 25S

Your boiler is temporarily locking out because the sensor that checks for the flame is not properly detecting it when the burner tries to ignite.

Reviewed by the BoilerFaultCodes Editorial Team · Last reviewed

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.

What the manual says

Manufacturer manual

Detection electrode

From this model's manual
Verified against the Biasi/Biasi Advance Plus Service 2012 installation & service manual.
Plain-English guidance below. Severity, DIY steps, costs and parts are our interpretation to help you act, not text from the manual.

Engineer required

This is a high severity fault. Stop using the boiler and call a Gas Safe registered engineer. Do not attempt gas-related repairs yourself.

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Related fault codes

H58View →Er04View →Er78View →

All 25 fault codes on the Advance Plus 25S

Seeing a different code? Every code this model can display, in one place.

7169-016An 11E01-204E01-205E23-792E83-101Er 01Er 02Er 03Er 04Er 05Er 06Er 07Er 08Er 09Er 10Er 11Er 14Er 99H58-661H74-550H74-553Li 01

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