⭐ Upgrade to Pro - £19
Unlock all lessons and mock exams to pass Level 2 + Level 3 theory exams.
Upgrade nowHot Water System Fault Finding
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
Fault finding on domestic hot water systems involves systematically identifying the causes of poor performance, overheating, unwanted system noises, and component failures. Recognizing common symptoms ensures you can diagnose defects safely and carry out effective maintenance.
Learning Objectives
Identify the primary causes of temperature, heating, and circulation failures in domestic hot water systems.
Diagnose sources of system noise, airlocks, and water contamination.
Recognise critical safety defects, including cylinder collapse and thermostat failure.
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.