Foundation · Unit 5
The Draw Warm Method: S-Plan
In short
Our way of wiring a heating system so that you can remember it on site. Start on the unwired S-Plan template and fill the wiring centre in the order the system works: L, N, E on 1, 2, 3, then heating on 4 and 5, hot water on 6 and 8, the oranges on 10. Every wire checked; the last lesson is from memory.
Comes after The parts.
In this unit
The Draw Warm Method: the parts on the wall
Every part of the S-Plan on the wall, and no wires yet: what each part does, and the story of the numbers.
How it opensIn this course you wire a whole S-PLAN heating system, one wire at a time. The parts are already on the wall, and nothing is wired yet.
Block 1: the permanent lives
The five wires that belong on block 1, the permanent live block - the zone valves' greys among them - and a continuity test that proves the block is one conductor.
Block 2: the neutrals
7 blue wires on block 2: every motor and every powered control gets its neutral, its way back to the supply.
Block 3: the earths, the supply proven
6 green-and-yellow wires on block 3, an earth test, then the spur on and the supply proven live.
Heating: blocks 4 and 5
The heating demand from the programmer's switch, through the room thermostat (stat), to the valve: two blocks, two wires each, the valve opening and springing back.
Hot water: blocks 6 and 8
The same story for the hot water: the programmer's switch, the cylinder thermostat (stat), the valve's motor - with block 7 left empty.
Block 10: the oranges, the boiler, the pump
The last wires are orange: they fire the boiler. Then the boiler runs the pump, and the system fires for the first time.
Commissioning: the truth table
Every demand state of the S-Plan, proven in turn: the truth table.
The practical: from memory
The supply is in. Wire the 12 sequence wires again: each step names the wire's job, not its block. Recorded.
The practical · recorded, no hints
You will learn to
- Land L, N and E first so only the sequence wires are left
- Know the zone valve grey as a permanent live - not brown
- Follow a demand from the programmer's switch through the stat to the valve motor, block by block
- Put every orange on one block: the only wires that fire the boiler
- Wire the S-Plan sequence from memory and commission it
Checks and credit
- A timed check at the end of the unit, its questions drawn at random. The score goes on your record.
- A practical with no hints, every step recorded.
- The unit earns the credential The Draw Warm Method: S-Plan (simulator).
- Also a short course on its own, The Draw Warm Method: S-Plan, with credit both ways.
Where it connects
The parts it uses
Wiring diagrams
Foundation
- The parts
Unit 4, before this one
- The Draw Warm Method: Y-Plan
Unit 6, next
Back to the Programme.
Read the explanation
- How the wiring centre’s numbered blocks tell the story of an S-Plan
An S-Plan wired in the order it works: the supply on blocks 1 to 3, heating on 4 and 5, hot water on 6 and 8, the valves’ orange cores on 10.
Practise it in the simulator.
Runs in the browser on a laptop or desktop. Cancel any time.