Electric Shower vs Mixer Shower in London: Which Is Right for Your Home
London homeowners choosing between an electric shower and a mixer shower face a genuine trade-off between installation flexibility, performance, and running cost. This guide explains both options clearly.
How Electric Showers Work
An electric shower heats water on demand using an electric heating element inside the unit. Cold water from the mains supply enters the unit and passes over the element, emerging from the showerhead at the selected temperature. The unit does not use stored hot water from the cylinder or boiler — it creates its own heat. This independence from the hot water system is the primary advantage of an electric shower in London properties: it works regardless of whether the boiler is running or whether the hot water cylinder has been exhausted by other users.
Electric showers are rated in kilowatts — typically 8.5kW, 9.5kW, or 10.5kW. The higher the kilowatt rating, the more heat the element can produce and the better the temperature and flow performance. A 10.5kW electric shower produces noticeably warmer and faster-flowing water than an 8.5kW model at the same inlet pressure. London mains cold water temperature is typically 8 to 12 degrees Celsius in winter and 15 to 18 degrees Celsius in summer. The element must raise the water from this inlet temperature to 40 to 42 degrees Celsius at the showerhead — a greater temperature rise in winter than summer.
How Mixer Showers Work
A mixer shower blends hot and cold water from the existing supply system before delivering the mixed water to the showerhead. A manual mixer shower uses a single lever to blend the supplies — the user adjusts the temperature by moving the lever. A thermostatic mixer shower incorporates a thermostatic cartridge that maintains a constant output temperature regardless of pressure fluctuations in the hot or cold supply. This prevents scalding or cold shock when someone flushes a toilet or turns on a tap elsewhere in the property — a genuine safety advantage in multi-occupancy London properties.
Mixer showers require a balanced hot and cold water supply at similar pressures. In properties with a combi boiler, both supplies are at mains pressure and are naturally balanced. In properties with a vented hot water cylinder and gravity-fed hot water, the pressure differential between the mains cold supply and the lower-pressure gravity-fed hot supply is a common cause of thermostatic mixer shower poor performance. A pressure-balancing valve or a pump on the hot supply can resolve this.
Installation Requirements
An electric shower installation requires a dedicated electrical circuit from the consumer unit — typically a 40A circuit for a 9.5kW or 10.5kW shower — and a cold water supply connection. No hot water supply connection is needed. The unit must be installed outside the shower zone and connected via an appropriate pull-cord switch or remote switch. Installation of an electric shower by a qualified plumber and electrician typically takes 3 to 5 hours including the consumer unit circuit and all connections.
A thermostatic mixer shower installation requires hot and cold water supply pipework in the shower enclosure, a suitable wall for the valve, and the showerhead and rail. Where the existing pipework does not reach the desired shower position, additional pipework is required. Installation typically takes 2 to 4 hours where pipework is accessible. Hidden pipework in tiled bathrooms requires more work if pipes need to be re-routed.
Which Is Better for a London Property
Electric showers are well suited to properties where the hot water system cannot reliably supply the shower — properties with a small hot water cylinder, properties where multiple occupants use the shower consecutively, or properties without a gas supply relying solely on an immersion heater. Mixer showers — particularly thermostatic mixers — deliver better performance (higher flow rate, more consistent temperature, larger showerhead options) and are the preferred choice when the water system can support them. For a London Victorian terrace with a vented system and low hot water pressure, upgrading to a combi boiler or fitting a shower pump alongside a thermostatic mixer shower transforms the shower performance. Contact Prestige Engineers for shower installation and upgrade advice across all London boroughs.