BoilerFaultCodes.com
S.25 Low

Your boiler is temporarily cooling itself down after finishing a cycle for hot water.

Technical description: DHW mode – pump or fan overrun error
Typical repair cost: £0-80 (including labour)

DIY fix possible

Check that at least one radiator or bypass valve is open to allow heat to dissipateWait for the code to disappear naturally as the boiler settlesEnsure there is enough water pressure shown on the digital display (1.0 to 1.5 bar)

Get professional help

Find a Gas Safe registered engineer in your area.

Find a Gas Safe engineer →

Protect yourself from future repair bills

A boiler cover plan would cover faults like S.25 — no call-out fees, no surprises.

Most popular
Hometree
from £12.95/month
Get a quote →
HomeServe
from £8.00/month
Get a quote →
Best value
YourRepair
from £7.99/month
Get a quote →

*Affiliate links — we may earn a commission at no extra cost to you. Prices shown are starting prices.

Parts commonly replaced

*Affiliate links — we may earn a commission at no extra cost to you.

Related fault codes