Electric Showers and Their Supply Requirements
An electric shower heats cold mains water as it passes through, so it works even when the boiler is off.
An electric shower heats cold mains water as it passes through, so it works even when the boiler is off. Its performance is fixed by the kilowatt rating and the incoming cold flow, not by your hot water system.
Why winter showers feel weaker
Incoming mains water is colder, so the same heater raises it less. The unit reduces flow to hold temperature — the same appliance, harder conditions.
Electrical requirements
A dedicated circuit sized for the rating, correct protection and a properly located isolator. This is not a socket-and-plug appliance.
Scale is the usual killer
In hard water the heater element scales and the thermal cutout starts tripping. Softening or scale reduction extends unit life.
Choosing an electric shower
- Rating matched to the existing electrical supply
- Cold mains flow measured, not assumed
- Consideration of scale protection in hard water areas
Who does the work
- Gas Safe registered engineers — registration 554328
- Worcester Bosch accredited installer
- John The Plumb Ltd, company registration 10026483
Electric shower advice
Send us the model and rating and we will tell you what the supply and plumbing side would need.
Questions we get asked
Can I fit a higher kW unit?
Only if the circuit and supply support it. Upgrading the shower without upgrading the circuit is unsafe.
Why does mine cut out and restart?
Commonly a scaled element or a thermal cutout tripping, sometimes low flow triggering protection.
Are they cheaper to run?
They heat only what you use, but on electricity. Whether that beats a gas-heated shower depends on tariffs, so we make no claim either way.