⭐ Upgrade to Pro - £19
Unlock all lessons and mock exams to pass Level 2 + Level 3 theory exams.
Upgrade nowTesting Immersion Heaters
Read through the material below, then test your understanding.
Module Lessons
Electrical Principles & Diagnostics
Ohm's Law & Electrical Power
Protection Against Electric Shock
Electrical Statutory Regulations
BS 7671 & IET Guidance Documents
Reading Electrical Plans & Diagrams
Consumer Units & Protective Devices
Lighting & Power Circuits
Earthing, Bonding & ADS
Electrical Accessories
Current-Using Equipment & Specialist Controls
Effects of Electric Shock on the Body
Tool & Equipment Safety Classes
The Safe Isolation Procedure, Step-by-Step
Hand Tools for Electrical Work
Cable Types
BS 7671 Termination Requirements (Section 526)
Terminal & Connection Types
Cable Glands & Enclosure Entry
Terminating Flexes & Single-Core Cables
Terminating Flat Profile (Twin & Earth) Cable
Installing Main Protective Bonding
Fitting & Labelling BS 951 Bonding Clamps
Electrical Test Instruments
Central Heating Control Sequence of Operation
Diagnosing Boiler Thermostats & Fans
Diagnosing Air Pressure Switches
Diagnosing PCBs & Ignition Components
Diagnosing Thermocouples & Thermistors
Alternative & Emerging Heat Sources
Testing Immersion Heaters
Isolating & Correcting Appliance Faults
Lesson Overview
Testing domestic immersion heaters involves verifying supply circuit parameters, proving element electrical resistance, and conducting insulation resistance tests to identify breakdown, earth leakage, and faulty thermostats.
Learning Objectives
Explain the supply requirements and safety controls for immersion heaters under BS 7671 and Building Regulations Part G3.
Carry out dead testing procedures to measure heating element resistance and test thermostat switching.
Execute an insulation resistance test at 500 V DC to diagnose earth leakage faults and protect against RCBO tripping.
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.