Drainage for condensate from condensing boilers

Condensate from condensing boilers should be taken to a suitable drain. This condensate drain may be connected to sanitary pipework. The connection should be made with pipework having a minimum diameter of 22 mm and should incorporate a 75 mm condensate trap. Where the condensate trap is provided externally to the boiler, an air gap should be provided between the boiler and the trap with the condensate drain discharging into a suitable tundish upstream of the trap. The connection should preferably be made to an internal drainage stack. Where the connection is made to a branch pipe it should be connected downstream of any sink waste connection. All sanitary pipework into which condensate is to discharge, should be made of materials resistant to a pH value of 6.5 or lower and the installation should be in accordance with BS 6798. Where it is not practicable to follow the above provisions, alternative provision for the drainage of condensate from a condensing boiler is given in Appendix C of the "Guide to the Condensing Boiler Installation Assessment Procedure for Dwellings".