High
FAILURE TO LIGHT on Johnson Starley Warmcair DW

Your boiler is not firing up because it isn't receiving the correct signal from your thermostat or internal controllers to start the heating process.

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

External controls, port valves, or programmer issues. Includes checks for 230V on display SL and potential display or PCB replacement.

From this model's manual
Verified against the Johnson Starley Warmcair Dw 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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