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Read through the material below, then test your understanding.
Module Lessons
Hot Water Systems: Planning & Design
Fuels Used in Hot Water Systems
Open Vented Storage Systems
Unvented Storage Systems
Localised Water Heaters
Unvented System Pressures
Secondary Circulation Systems
Hot Water Safety Controls
Functional Controls: Strainers & PRVs
Expansion Devices & Check Valves
Pressure Relief, Tundish & Composite Valves
Discharge Pipework: Sizing & Termination
Design Information Sources
Sizing Cisterns & Storage Vessels
Hot Water Pipework Sizing
Sizing Circulation & Boosting Pumps
Sizing Expansion Vessels & Presenting Designs
Installing Unvented Hot Water Systems
Testing & Commissioning Hot Water Systems
Diagnosing Hot Water System Faults
Component Fault-Finding: Pumps, Vessels & Thermostats
Servicing & Maintaining Hot Water Systems
Lesson Overview
Open vented hot water storage systems rely on a cold water cistern and an open vent pipe to maintain atmospheric pressure and deliver domestic hot water safely by gravity.
Learning Objectives
Identify the layout and installation requirements for open vented direct and indirect hot water systems.
Explain the statutory sizing, pipework positioning, and venting rules designed to prevent parasitic circulation and over-pressurisation.
Compare the design characteristics, components, and regulatory restrictions governing direct, double-feed, and single-feed cylinders.
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