BoilerFaultCodes.com
S.31 Low

Your boiler is currently set to summer mode, which means it is only providing hot water and has intentionally ignored the request for central heating.

Technical description: No heat demand summer operating mode
Typical repair cost: £0 (including labour)

DIY fix possible

Locate the radiator temperature dial or button on the boiler control panel.Turn the dial clockwise or adjust the setting to increase the target heating temperature.Ensure your wall thermostat or heating programmer is also set to 'On' or a high temperature.

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.31 — 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.

Related fault codes