Hi - problem is that when tap is turned off there is a loud banging / hammer noise from the pipework. Most noticable on pipe to bathroom sink which is upstairs. Problem can be avoided if tap is turned off very slowly. Any help would be appreciated. Many thanks.
I've checked water hammer project as suggested but it seems to deal with problem with valve in tank. There is no tank as system is fed from the mains. The hammer occurs when the hot water is turned off. Many thanks - Steve
check water pipes are secure, normally just a pipe vibrating, against another or against joist or floor board. If pipes are secure see if they touch anywhere, and insulate or lag pipes with foam or something similar. or try closing the mains stop tap slightly just to reduce the pressure entering the property.