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Department for Energy Security and Net Zero

Showers

1.1 Scope

This sub-technology relates to non-domestic showers, including instant water heating electric showers that may be used in non-domestic applications. 

Note special use cases, for example emergency use showers are excluded from the scope. 

The ETL Scheme covers four product categories: 

  • Shower valves: A flow regulating device incorporating a flow regulator housed inside a dedicated fitting that may also include isolating valves and check valves as part of the design. 
  • Shower heads: A device that controls the spray of water in a shower. It is used to describe any relevant hand shower or fixed head outlet (body or side jets are excluded from the scope of these criteria). 
  • Shower System: This includes both the shower head (whether hand shower or overhead, or both) and mixing valve. 
  • Electric showers: Showers that electrically heat the water as flow is opened. For the purposes of the ETL, these are comprised of a hand shower, flexible hose and shower heating unit. 

To be eligible for inclusion on the ETL, products shall meet the requirements as set out below. 

1.2 Definitions

  • An energy saving shower is where the total water volume used is as low as possible, without impacting on user experience, therefore these criteria take into consideration flow and shower duration. 
  • User behaviour features (UBFs) are an important parameter assisting the reduction of shower duration. They are defined as: built in shower features that impact on or react to user behaviours to reduce total water volume used per shower. These include push valves, shower duration or resource consumption displays, timed shut off valves and water or temperature breaks. 

Showers are available in a range of different designs and efficiencies. The Energy Technology List (ETL) Scheme aims to encourage the purchase of higher efficiency products. 

1.3 Requirements

1.3.1 Eligibility requirements

To be eligible: 

All products shall: 

  • Demonstrate they are for non-domestic applications through the provision of product literature and meet all relevant legislation. 

Shower valves shall: 

  • Have a thermostatic valve (except for electric showers) 
  • Comply with EN 1111:2017 Sanitary tapware. Thermostatic mixing valves (PN 10). General technical specification (as applicable). 
  • Comply with EN 1287:2017 Sanitary tapware -Low pressure thermostatic mixing valves - General technical specification (as applicable). 

Shower heads shall: 

  • Comply with BS EN 1112:2008 Sanitary tapware, which specifies the dimensional, leak tightness, mechanical, hydraulic and acoustic characteristics with which shower outlets shall comply (as applicable). 

Shower systems shall: 

  • Comply with the eligibility requirements set out above for both shower valves and shower heads. 

Electric showers shall: 

  • Comply with all relevant safety standards. 

1.3.2 Performance requirements

Products shall meet the following performance requirements applicable to their product category: 

  • Shower valves

– Provide a maximum available flow rate (Qmax) at 9 l/min without user behaviour features, and 10.6 l/min with UBFs incorporated. 

– Achieve pressure independency in line with testing requirements within section 1.4.3.2 below. 

  • Shower heads

– Provide a maximum available flow rate (Qmax) at 9 l/min without user behaviour features, and 10.6 l/min with UBFs incorporated. 

– Achieve pressure independency in line with testing requirements within section 1.4.3.2 below. 

– Achieve spray coverage in line with testing requirements within section 1.4.3.3 below. 

  • Shower systems

– Provide a maximum available flow rate (Qmax) at 9 l/min without user behaviour features, and 10.6 l/min with UBFs incorporated. 

– Achieve pressure independency in line with testing requirements within section 1.4.3.2 below. 

– Achieve spray coverage in line with testing requirements within section 1.4.3.3 below. 

  • Electric showers

– Maximum available flow rate (Qmax) at 4.5 l/min.

1.4 Measurement and calculations 

1.4.1 Performance metrics 

The three main performance metrics as outlined in the performance requirements above (flow rate, pressure independency and spray coverage) shall fulfil the requirements within the UWL scheme as published in January 2023 (as amended)1

1.4.2 Measurement standards 

The following standards, where applicable, shall be used to determine product eligibility: 

  • EN 1111:2017 Sanitary tapware. Thermostatic mixing valves (PN 10). General technical specification 
  • EN 1287:2017 Sanitary tapware - Low pressure thermostatic mixing valves - General technical specification 
  • BS EN 1112:2008 Shower outlets for sanitary tapware for water supply systems type 1 and type 2. General technical specification. 

The following standard, where applicable, shall be used to determine product performance: 

  • Unified Water Label (UWL) scheme as published in January 2023. 

1.4.3 Test Requirements 

1.4.3.1 Flow rate testing 

  • Procedure for testing mixer showers (shower valves) and shower outlets (shower heads) to follow the Unified Water Label (UWL) scheme as published in January 2023. 

The maximum flow rate (Qmax) shall be calculated in line with the Unified Water Label scheme (UWL) scheme as published in January 2023: 

1. Connect the shower outlet/valve to the test apparatus 

2. Adjust the shower plate horizontally facing downwards 

3. Make sure that pressure P2 is reached at the centre of the face plate of the shower head 

4. Report flow rate Q after stabilization 

  • Procedure for testing electric showers to follow the formula for flow rate calculation in line with Unified Water Label (UWL) scheme as published in January 2023, as per Table 1.1. 

Table 1.1 Fixed parameters for flow rate calculation 

Fixed parameters for flow rate calculation  
Outlet temperature 42oC
Inlet temperature 15oC
Operating voltage 240V
Density of water ~1kg/l
Specific heat capacity of water 4,18 kJ/(kg K)

 

 

1.4.3.2 Pressure independency 

  • To comply with the following requirement as outlined within the UWL published in January 2023:

The lowest flow rate shall not be less than 60 % of the maximum flow rate.
Where: 

– the flow rate at the reference pressure (3 bar) is ≤ 8.0 l/min and 

– the flow rate at the lower pressure (1.5 bar) shall be ≥ 60 % of the maximum available flow rate 

1.4.3.3 Spray coverage 

  • To follow the testing procedure for shower outlets (shower heads) as identified within the UWL scheme as published in January 2023. 

1.4.4 Rounding 

There shall be no benefit gained by applicants from rounding the performance requirements. 

1.5 Verification for ETL Listing

Any of the following testing routes may be used to demonstrate the conformity of products against the requirements: 

  • In-house testing – Self-tested and verified or cross-checked by an independent body 
  • Witnessed testing 
  • Independent testing 
  • Representative testing (see clause 1.5.1) 

Further information regarding the first three routes can be found in the ETL Testing framework

1.5.1 Representative testing 

Where applications are being made for two or more models that are variants of the same basic design, test data may be submitted for a single ‘representative model’ provided that all variants: 

  • Fall within the same product category. 
  • Have the same maximum available flow rate; with or without UBFs as applicable. 

Applicant to provide justification how the representative model has similar or worse performance in terms of pressure independency and spray coverage. 

It should be noted that: 

  • If a manufacturer voluntarily removes the representative model from the ETL then other products linked with that representative model may or may not be permitted to remain on the ETL. 
  • If any product submitted under these representative model rules is later found not to meet the performance criteria when independently tested, then all products based on the same representative model will be removed from the ETL. 

1.6 Conformity testing 

Products listed on the ETL may be subject to the scheme’s conformity assessment programme in order to ensure listed models continue to meet the ETL requirements. 

1.7 Review

1.7.1 Indicative review date 

This specification is scheduled to be reviewed during the 2024/25 review cycle. 

1.7.2 Illustrative future direction of the requirements 

The first technical review of these criteria will consider: 

  • The standards developed under the EC Mandate by the European Committee for Standardisation on performance of taps and showers.