⭐ Upgrade to Pro - £19
Unlock all lessons and mock exams to pass Level 2 + Level 3 theory exams.
Upgrade nowHot Water Safety Controls
Read through the material below, then test your understanding.
Module Lessons
Hot Water
Hot Water Legislation and Standards
System Selection Factors
Open Vented Hot Water Systems
Hot Water Storage Cylinders
Combination and Quick Recovery Cylinders
Unvented Hot Water Systems
Localised Hot Water Systems
Hot Water Safety Controls
Discharge Pipework (D1/D2)
Decommissioning Hot Water Systems
Thermostatic Mixing Valves (TMVs)
Installing Shower Mixing Valves
Replacing Hot Water Components
Expansion of Hot Water Pipework
Testing and Inspecting Hot Water Systems
Hot Water System Fault Finding
Maintenance and Component Replacement
Lesson Overview
This lesson covers the critical safety and functional controls required to prevent overheating, excessive pressure, and scalding in domestic hot water systems.
Learning Objectives
Explain the three-tier safety mechanism required on unvented hot water storage systems
Identify the operating temperatures and functions of thermostats, relief valves, and open vents
Describe the role of functional controls in protecting hot water systems from over-pressurisation and backflow
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.