Criteria for: Efficient Toilets, Low flush toilets

Low flush toilets

New water flushed appliances may be eligible for inclusion in the Water Technology List if they meet the appropriate requirements of the Water Supply (Water Fittings) Regulations 1999, Regulator’s Specification for WC Suites, as set out in section 4, (see page 2 at the end of this document).

The physical endurance and leakage requirements of the flushing device are as follows: when tested as described in Clause 9 of the Regulator’s Specification, the flushing device shall not undergo any failure or permanent distortion of any components including linkages that prevents normal operation of the mechanism. In addition, no instances of leakage are permitted. A leak is defined as being visible discharge of water amounting to more than 3 separate drops.
Compliance may be demonstrated by WRAS* approval (* or other independent test laboratory accredited to ISO 17025). Alternatively companies accredited to ISO 9001 may provide a declaration of self-conformity with the Regulations.

New water flushed appliances must have an Effective Flush volume of 4.5 litres or less.
 
For dual flush WCs the ratio full flush:reduced flush is taken to be 1:3 (this ratio is used in the specification of the outlet Valve Endurance Test from the Regulator’s Specification for WC Suites). This allows the determination of an Effective Flush (EF) volume for a dual flush WC, e.g. a 6/4 litre dual flush has an EF of 4.5 litres. For a single flush WC the maximum flush volume is taken to be the EF (4.5 litres).
  
 The items that are covered in the specification are for complete suites, not discrete pans and cisterns. 

Manufacturers should apply to Defra with evidence that their products meet these criteria in order to appear on the Water Technology List.