Low
S.98 on British Gas 330+

Your boiler is currently running a self-diagnostic test on its internal sensors and has temporarily paused providing heat or hot water while it checks itself.

Reviewed by the BoilerFaultCodes Editorial Team · Last reviewed

Monitor it

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.

What the manual says

Manufacturer manual

Flow/Return-Sensor check is running, demand (dhw or heating) is blocked. Check flow & return thermistor connections to pipes. Check harness connection to thermistor. Check harness wires are not trapped between any internal components.

From this model's manual
Verified against the British Gas 330 installation & service manual, page 47.
Plain-English guidance below. Severity, DIY steps, costs and parts are our interpretation to help you act, not text from the manual.

Engineer required

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

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Related fault codes

S.97View →F.22View →F.23View →F.24View →

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