BoilerFaultCodes.com
S.14 Medium Information

Your boiler is confused and thinks you are asking for hot water even though your taps are turned off, preventing the heating from starting.

Book a service

This fault should be looked at by a Gas Safe engineer within the next week or two. It may get worse if left.

Technical description: Hot water demand via fan sensor error

What causes this fault?

This fault occurs when the boiler's internal flow sensor incorrectly detects that water is running through the hot water pipes, even when all your taps are closed. The most common reason is a sticking internal component or a faulty sensor that is sending a false signal to the boiler's brain. Because the boiler thinks you are prioritising a hot bath or shower, it refuses to switch over to provide heat for your radiators.

Typical repair cost £100-220 (including labour)

Engineer required

This fault requires a Gas Safe registered engineer. Do not attempt gas-related repairs yourself.

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.14 — no call-out fees, no surprises.

Top rated
OpenFix
Boiler & heating care plans
Get a quote →
Hometree
from £12.95/month
Get a quote →
HomeServe
from £8.00/month
Get a quote →

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

Related fault codes