High
lockout LED 2 ON on Ideal Response

Your boiler has tried to light several times but cannot detect a flame, causing the system to shut down for safety.

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

Ignition Control PCB 41 has attempted 4 ignitions and failed. Flame not detected.

From this model's manual
Verified against the Response 80 100 120 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.

What causes this fault?

This fault occurs because the boiler's control system cannot confirm that a flame has successfully lit after several attempts. It is usually caused by a lack of gas reaching the burner, a worn-out ignition spark electrode, or a dirty sensor that can no longer 'see' the flame even if it is there. The boiler shuts down as a safety precaution to prevents unburnt gas from building up inside the unit.

This issue can be more frequent during the first cold snap of winter when components that have been idle all summer are suddenly forced to work under high demand.

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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