Johnson & Starley S253-0506000 Flame Control Device

The Johnson & Starley S253-0506000 is a flame control device used on Johnson & Starley gas boilers. It sits in the boiler's control circuit and governs the flame detection and burner sequencing side of appliance operation. The part is listed under boiler controls and gas boiler spares.

• The boiler runs through its ignition sequence but fails to establish or hold a flame, leading to lockout.
• Repeated lockouts on start-up or during a demand for heat that clear only after a reset.
• The burner lights briefly and then shuts down, with the appliance cycling instead of running steadily.
• Flame detection behaves inconsistently, working on some calls for heat and failing on others.

• Confirm the boiler model on the appliance data plate matches the fitment list above.
• Check the existing control device carries the part number S253-0506000 before ordering.
• Verify the fault is traced to the flame control circuit rather than the electrode, lead or gas supply.
• Isolate the electrical supply and follow the manufacturer's instructions for access and replacement.