Selection Criteria Electric showers
What is an electric shower?
An electric shower supplies hot water on demand by directly heating cold water using an electric element. This is different to a standard shower which uses both cold and hot water straight from your hot water supply e.g., water heated by your boiler.
For more details on what an electric shower is, how it works and tips for installation, please see our Product Guide.
Introduction
This page details the selection criteria applied to electric showers on toptenuk.org. Since all electric showers are all effectively greater than 99% efficient, the energy used by them is directly related to the amount of water used, so by using a product with a lower flow rate, you’ll be saving energy and therefore reducing emissions.
Selection Criteria
The minimum criteria to be shown on toptenuk.org are shown below:
- Listed on the official product database of the Unified Water Label
- 7.5kW rating or lower
Unified Water Label Database
The products on the ToptenUK website have to be listed on the Unified Water Label’s dedicated database. Electric showers on this database receive the Unified Water Label efficient product mark (Figure 1).

Figure 1: Unified Water Label Efficient Product Mark
Regulations
Electric showers come under the Ecodesign and Eco labelling design requirements for water heaters. The following EU regulations cover electric showers:
Energy labelling: Commission Delegated Regulation (EU) No 812/2013 of 18 February 2013 supplementing Directive 2010/30/EU of the European Parliament and of the Council with regard to the energy labelling of water heaters, hot water storage tanks and packages of water heater and solar device (Text with EEA relevance)
Eco-design: Commission Regulation (EU) No 814/2013 of 2 August 2013 implementing Directive 2009/125/EC of the European Parliament and of the Council with regard to ecodesign requirements for water heaters and hot water storage tanks (Text with EEA relevance)
Glossary
Energy rating
The energy class of the heating element contained within the shower (heating) unit as indicated by the energy label.

Figure 2: Example energy label for electric shower
Annual energy consumption (kWh/year)
Electricity consumption in kilowatt hours (kWh) per year, according to the energy label.
Flow rate
The volume of water, in litres, that passes through the shower in a minute as indicated on the Unified Water Label database.
Further details of how the scheme calculates the flow rate of electric showers can be found here.
Power rating (kW)
The maximum energy the electric shower will use in order to heat and supply water. See Mira’s guide here for more details - https://www.mirashowers.co.uk/blog/mira-recommends...
Estimated electricity cost per year
Annual Energy Consumption according to the energy label x Electricity Costs at 28.3 pence/kWh (Energy Saving Trust)
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