Water Supply Industry Interpretations and Advice

  • Area of Interest : WCs
  • Topic : Warning pipes
  • Title : Internal warning pipes (overflows)
  • Clause Reference : Schedule 2 paragraph 25 (1)(h) & G25.8
  • Reference Number : WC01
  • Decision Date : June & October 2000

The use of internal warning pipes (standing overflows) in WC flushing cisterns, such that overflowing water is discharged into the back of the WC pan, is accepted as an equally effective device to an external warning pipe.

This acceptance is subject to:-

  • the cistern inlet valve being of a type which meets the performance requirements of the Regulators’ WC Specification; and
  • inlet valves of a compact type (e.g. those manufactured to BS1212 Part 4) having a strainer fitted up-stream of the float operated valve to trap debris (swarf etc.) which might cause premature failure of the valve.