https://jme-training-academy.com/index.php?action=history&feed=atom&title=S-Plan_Wiring_Reference_PackS-Plan Wiring Reference Pack - Revision history2026-06-15T12:10:05ZRevision history for this page on the wikiMediaWiki 1.45.3https://jme-training-academy.com/index.php?title=S-Plan_Wiring_Reference_Pack&diff=27&oldid=prevMorgan Allen: Created page with "= S-Plan Heating System Wiring Reference = == Overview == S-Plan systems use separate 2-port valves for heating and hot water control. == Main Components == * Boiler * Programmer / timer * Room thermostat * Cylinder thermostat * 2 × 2-port motorised zone valves (heating + hot water) * Pump * Junction box / wiring centre --- == System Operation == * Heating and hot water are independently controlled. * Each zone has its own valve. * Each valve provides a separate boi..."2026-06-10T14:08:28Z<p>Created page with "= S-Plan Heating System Wiring Reference = == Overview == S-Plan systems use separate 2-port valves for heating and hot water control. == Main Components == * Boiler * Programmer / timer * Room thermostat * Cylinder thermostat * 2 × 2-port motorised zone valves (heating + hot water) * Pump * Junction box / wiring centre --- == System Operation == * Heating and hot water are independently controlled. * Each zone has its own valve. * Each valve provides a separate boi..."</p>
<p><b>New page</b></p><div>= S-Plan Heating System Wiring Reference =<br />
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== Overview ==<br />
S-Plan systems use separate 2-port valves for heating and hot water control.<br />
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== Main Components ==<br />
* Boiler<br />
* Programmer / timer<br />
* Room thermostat<br />
* Cylinder thermostat<br />
* 2 × 2-port motorised zone valves (heating + hot water)<br />
* Pump<br />
* Junction box / wiring centre<br />
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== System Operation ==<br />
* Heating and hot water are independently controlled.<br />
* Each zone has its own valve.<br />
* Each valve provides a separate boiler demand signal.<br />
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== Wiring Concept (Signal Flow) ==<br />
* Programmer sends switched live to each zone<br />
* Thermostat/cylinder thermostat controls valve opening<br />
* End switch in each valve signals boiler demand<br />
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== Key Wiring Points ==<br />
* Heating valve controls radiator circuit<br />
* Hot water valve controls cylinder circuit<br />
* Either valve end switch can trigger boiler<br />
* Neutral connections commoned in wiring centre<br />
* Earth continuity maintained across all components<br />
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== Common Fault Areas ==<br />
* One zone not opening (failed actuator)<br />
* No boiler firing (end switch fault)<br />
* Crossed heating/hot water controls<br />
* Incorrect programmer configuration<br />
* Sticking valve heads<br />
* Wiring centre misconnection after maintenance<br />
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== Notes ==<br />
* S-Plan is easier to fault-find than Y-Plan due to separate zones.<br />
* Always isolate valves before replacing heads.</div>Morgan Allen