An electric shower draws more current than almost anything else in a domestic property. That means both of its common failure modes are visible at the consumer unit: a heating element breaking down internally, or a supply cable and protective device that were never quite right for the shower fitted.
Element failure
If the shower trips the RCD partway through use, particularly once the water is hot, the element is the prime suspect. Insulation resistance testing on the shower circuit with the shower isolated versus connected separates the appliance from the wiring quickly.
Undersized supply
Where a higher-rated shower has been swapped in over the years without upgrading the cable or protective device, the MCB trips on load rather than leakage — often only when the shower runs at full heat in winter. That is a wiring job, not an appliance job.
What good looks like
A dedicated circuit, correctly sized cable, an appropriately rated protective device, a pull-cord or accessible isolator, and correct bonding. We check all of it and provide certification, because shower circuits are the ones most often found to be substandard during an EICR.
Common questions
- Can I fit a more powerful shower?
- Only if the circuit supports it. We will confirm cable size and protection before you buy.
- Is a tripping shower dangerous?
- The protective device is doing its job, but a breaking-down element should be replaced rather than lived with.
- Do you fit showers?
- We handle the electrical side — supply, isolation, testing and certification. Plumbing connection is separate.
- Will this show on an EICR?
- An undersized or unprotected shower circuit will typically be coded, yes.
Let us know the shower's kW rating and we can tell you what supply it should have.
Related guides
- Bathroom Electrics and ZonesBathrooms are a special location, and the rules are about water and distance rather than paperwork for its own sake.
- EICR Codes C1, C2, C3 and FI ExplainedFour codes decide whether your report is satisfactory and what you must do next.
- Why Your Fuse Box Keeps TrippingA consumer unit that trips is doing its job — the question is what it keeps objecting to.