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Upgrade nowSealed Central Heating Systems
Read through the material below, then test your understanding.
Module Lessons
Central Heating
Introduction to Central Heating & Part L
Heat Emitters: Radiators and Convectors
Radiator Valves: TRVs and Lockshields
System Layouts: One-Pipe and Two-Pipe
System Layouts: Microbore and Manifold
Boiler Types: Regular, System, and Combination
Condensing Boiler Principles
Open Vented Central Heating Systems
Sealed Central Heating Systems
Expansion Vessels and Pressure Relief
Central Heating Pumps and Circulators
System Controls: Programmers and Thermostats
Motorised Valves: 2-Port and 3-Port
Fully Pumped Systems: The Y-Plan
Fully Pumped Systems: The S-Plan
Filling, Venting, and System Balancing
Water Treatment and System Protection
Lesson Overview
A sealed central heating system operates under pressure and is closed to the atmosphere, removing the need for a feed and expansion cistern in the roof space. It relies on an expansion vessel, a pressure relief valve, and a filling device to manage system expansion, safety, and water replenishment.
Learning Objectives
Identify the core components and layout features of a domestic sealed central heating system.
Explain the methods of system filling and the required backflow prevention devices.
State the operational pressures, component positions, and the advantages and disadvantages of sealed systems.
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