High
Boiler lock out on Ferroli F24b

Your boiler has stopped working for safety reasons and needs a manual reset or a check of your gas and water drainage systems.

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

In the event of the red lockout light coming on. Check gas supply or condensate discarge. Clean condensate discharge if dyirty or obstructed.

From this model's manual
Verified against the Ferroli F24b 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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