⭐ Upgrade to Pro - £19
Unlock all lessons and mock exams to pass Level 2 + Level 3 theory exams.
Upgrade now3-Port Valve Systems: Y-Plan & W-Plan
Read through the material below, then test your understanding.
Module Lessons
Central Heating: Design & Controls
Building Regulations Part L & Boiler Interlock
Sealed Heating System Layouts
2-Port Valve Systems: S-Plan & S-Plan Plus
3-Port Valve Systems: Y-Plan & W-Plan
System & Combination Boilers
Multiple Boilers & Low Loss Headers
Heating Controls & Components
Advanced Heating Controls
Selecting Systems & Controls for Dwellings
Underfloor Heating: Design & Layout
Underfloor Heating: Pipework & Commissioning
Selecting Heating System & Component Types
Design Information Sources
Heat Loss & Heat Gain Principles
Calculating Room Heating Requirements
Sizing Heating Pipework & Circulating Pumps
Selecting Central Heating Boilers
Sizing Expansion Vessels & F&E Cisterns
Calculating Central Heating Component Sizes
Positioning Heating System Components
Wiring Combi & Gravity Hot Water (C-Plan)
Wiring 3-Port Valve Systems
Wiring 2-Port Valve Systems
Wiring Advanced Controls & Frost Protection
Safe Isolation & Electrical Testing
Commissioning Standards & Regulations
Planning & Preparing the Commissioning Test
Flushing & Hydraulic Testing
Water Treatment: Cleansers, Neutralisers & Inhibitors
Power Flushing
System Balancing
Compliance Certificates & Notification of Work
Central Heating Component Anatomy
Gathering Fault Information
Using Manufacturer Instructions for Diagnosis
Methods of Repairing Central Heating Faults
Safe Isolation During Maintenance & Repair
Diagnostic Testing Procedures for Faults
Alternative Wiring Arrangements
Lesson Overview
Master the design, hydraulic layouts, and operational principles of fully pumped central heating systems using 3-port mid-position (Y-Plan) and diverter (W-Plan) valves.
Learning Objectives
Distinguish between mid-position (Y-Plan) and diverter (W-Plan) valve operation and port configurations.
Identify core system components, including port designations and automatic bypass valves.
Apply sizing principles and priority heating logic to 3-port domestic installations.
Unlock the full lesson & knowledge check
Get lifetime access to every Level 2 & 3 lesson, 3500+ total questions, and timed City & Guilds mock exams.
Get Pro Access (£19)Already have Pro? Sign in
Interactive City & Guilds Level 2 and Level 3 plumbing lessons, flashcards and mock exams, built for UK students and professionals.
© 2026 PlumbingIQ. All rights reserved.