How to Test Electric Shower Components: A Complete DIY Diagnostic Guide [2026]

⚠️ SAFETY FIRST: READ BEFORE STARTING

Working on electric showers is dangerous. You are dealing with a high-voltage appliance (240V) and water.

• ISOLATE POWER: Always turn off the electricity at the main consumer unit (fuse box) and pull the isolation cord before removing the shower cover.

• VERIFY DEAD: Use a voltage tester to ensure no power is reaching the unit.

• LEGALS: In the UK, major electrical work in bathrooms is "Part P" regulated. If you are not a competent person or are unsure of these tests, stop and consult a Part P qualified electrician.

• DISCLAIMER: You follow these guides at your own risk. This site and its authors are not liable for any injury, loss, or damage caused by your repairs.

Struggling with a broken shower? Before you buy replacement parts, you need to know exactly which component has failed. In this electric shower diagnostic guide, I’ll show you how to use a multimeter to test every internal part, including the solenoid valve, thermal cut-out (TCO), and heating elements. Watch the full tear-down video below to see how to identify faults safely and save on expensive repair bills.

Video of how to test the components of an electric shower unit 

Here i go through some of the basic steps to trouble shooting an electrical shower unit . I will go over the tests individually in later posts and in more detail. 

Parts Link: Need a Multimeter for testing try on Ebay UK here

Tools Required: Multimeter (set to Ohms), Screwdriver set, Torch.

      Video on testing all components inside an Electric shower

Video showing whats inside and a complete tear down of an electric shower 

Testing electric shower parts is the only way to be 100% sure what is broken before you spend money on spares. In this video, I walk you through:

• Testing the Solenoid Coil: How to set your multimeter to Ohms (Omega) to check for a broken internal wire.

• Checking Heating Elements: How to identify if one of your two elements has burnt out (which causes lukewarm water).

• Testing the TCO (Thermal Cut-Out): A simple continuity test to see if the safety switch has "blown."

• The Microswitches: Ensuring the mechanical switches are actually making an electrical connection when the shower is turned on.

Testing the solenoid   ~ Fixes "No Water" issues.

Testing the Pressure relief valve Fixes "Leaking from bottom" issues

Testing the Heater element  Fixes "No Heat" issues

See our troubleshooting checklist guide Here