Hi I've got thumping coming from pipework when shower is shut off and when coldwater feed to washing machine cuts out, and sometimes when taps are switched off. I've lagged and screwed loose piping ( and in the loft), but thumping still happening. I have a combi boiler, so no cold water tank in loft. If I reduce the water flow at stopcock where supply enters the house, will this cure it?
Try closing the mains stop tap slightly this can sometimes help. If not or if the flow is not good enough for showering etc you can buy a shock arrestor, like a expansion vessel - rubber diaphragm one side air the other is the water - the diaphragm/air absorbs the shock/waves in the water and reduces the noise.
Hi HTG, thanks for the reply, tried reducing the flow by closing mains tap. stopped thumping on taps, but not at shower! its just as bad. Should I get a plumber to fit shock arrrester, and at the same timecheck over/replace shower control? Thanks Ian
Fitting the shock arrestor is pretty simple and easy enough for a DIYer, you may find once this is fitted the shower will be okay.
If you're not sure/confident what to do then yes ask a reputable plumber to fit the shock arrestor, and check the shower if this doesn't solve the banging problem. Ask friends/family for recommendations for a decent plumber.
The banging pipes may be annoying - but that is all. It's not dangerous and very unlikely to cause any damage.