Heatline S.08 Fault Code
Also written as S08 — same fault.
The Heatline S.08 fault code means: your boiler is currently taking a temporary rest pause between heating cycles to prevent excessive wear and tear, which is a normal part of its operation.. It appears on 8 Heatline models in our database.
Technical description: Time delay anti short-cycles after heating
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 →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 27 April 2026