How much does it cost to fix Heatline error code S.98?

Typical repair cost for the Heatline S.98 fault is £150-300 including labour.

S.98 High

Heatline S.98 Fault Code

Q: What does the Heatline S.98 fault code mean?

Your boiler has detected that hot water cannot flow through the pipes properly, which has caused it to stop working for your radiators and taps.

Also written as S98 — same fault.

The Heatline S.98 fault code means: your boiler has detected that hot water cannot flow through the pipes properly, which has caused it to stop working for your radiators and taps.. It appears on 8 Heatline models in our database.

Technical description: Flow/Return sensor control, DHW and CH is in blockage

Typical repair cost £150-300 (including labour)

Engineer required

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

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Heatline models that show the S.98 fault code

Click a model for the full fault code list and model-specific repair notes.

Source

Heatline S.98 fault code information on this page is sourced and cross-checked against the official Heatline service / installation manuals for each affected model.

Reviewed by the BoilerFaultCodes Editorial Team · Last reviewed 27 April 2026