BoilerFaultCodesYour boiler is currently preparing the burner to provide hot water, which is a normal part of its operation.
This is a minor fault. Keep an eye on it and mention it at your next annual boiler service. Reset the boiler and see if it clears.
Technical description: Hotwaterhandlingmode:Burnerignition
What causes this fault?
This code appears when the boiler detects a demand for hot water and is physically firing up the burner to meet that request. It is a normal part of the start-up sequence and indicates that the internal components are working correctly to heat your water. You will typically see this briefly on the display every time you turn on a hot tap or shower.
DIY fix possible
This fault may be fixable without an engineer. Check your manual first.
Find a Gas Safe engineer
Search the official register for a qualified engineer in your area.
Gas Safe Register →Protect yourself from future repair bills
A boiler cover plan would cover faults like S.23 — no call-out fees, no surprises.
Affiliate links — we may earn a commission at no extra cost to you.