S.08 Low

Heatline S.08 Fault Code

Also written as S08 — same fault.

The Heatline S.08 fault code means: your boiler is temporarily resting between heating cycles to prevent the system from turning on and off too quickly, which protects the components from wear and tear.. It appears on 7 Heatline models in our database.

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.

Technical description: Time delay anti short-cycles after heating
Typical repair cost £0 (including labour)

DIY fix possible

Wait approximately 5 to 15 minutes for the countdown to endEnsure radiators are turned up and thermostatic valves are openCheck that the room thermostat is calling for heat

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Heatline models that show the S.08 fault code

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

Source

Heatline S.08 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 31 August 2026