BoilerFaultCodesWhat the manual says
Manufacturer manualignition
From this model's manual
Verified against the Glow Worm Ultracom 2 Cxi installation & service manual, page 52.
What causes this fault?
This fault occurs when the boiler attempts to start up but fails to establish or detect a flame. The most common reasons include a worn-out ignition probe that can no longer create a spark, or a gas valve that isn't opening correctly to let fuel into the burner.
This issue can be more frequent during the first cold snap of autumn when internal 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.
Find a Gas Safe engineer
Search the official register →
Boiler cover options
Avoid the next call-out bill
A cover plan would handle faults like S.23: no call-out fees, no surprise bills.
Approved partner
Get a quote →
Domestic Appliance Guard
Unlimited call-outs, 24/7 helpline, no price-hike promise
Affiliate links. We may earn a commission at no extra cost to you.