Hi, any plumbers out there, new property and the cold water feed to the hot water tank rattles when it’s filling. Plumber that’s been out has said it’s the high incoming pressure causing it so he’s turned the gate valve down on the feed to the tank to stop this. Now I think this is a bit of a bodge would it be better to fit a flow restrictor into the 22mm incoming feed.

Any comments / suggestions greatly appreciated

Just fix the pipes better surely? I had this problem when the ballcock valve is fully open on my roof tank, and a zip tie round a rafter and the inlet pipe stopped the banging.

pipes are apparently securly clipped, it’s my mates house not mine, I’d have put a proper flow restrictor in 🙂

What about turning the valve down slightly on the feed to the hot water tank?

If it is an unvented cylinder, Megaflo type, then it sounds like the cold water combination valve ratling, replace, or if in area of very high pressure fit additional pressure reducing valve before it. Megaflo’s had a problem with their ones but could affect othere I suspect. Could be diaphram in expansion vessel vibrating also.

It could be that the size of the opening at the end of the pipe – in the ball valve presumably – is causing a flow restriction and inducing something call “water hammer” in the pipes where a stationary pressure wave is set up from the valve back up the pipe (a bit like air vibrating in an organ pipe). This causes the pipe to vibrate. In this case, reducing the inlet pressure is a perfectly good way to control the problem.