Bathroom tap

the main pressure in pipe (Don't know why, obviously installed by an idiot!)

Assuming you mean the cold water is run off the main or is the hot water running of the main via a combi boiler or the likes?. You say "obviously installed by an idiot"?, in this case our country is full of idiots including me as my cold water & hot water (via a combi boiler) run direct of the mains!

As to your problem, could be your system has an 'air lock' or you may have to gag the main stop c*ck because of too much pressure?.

Bet you didn't gripe while it was running of the main for those years, so something has changed or happened to cause the problem or has some 'idiot been fiddling'!

Mike P

Oops! Matthew not Mathew. Mike P

Sounds like the washer might be bouncing. Might be caused by an increase in pressure after it -- has the tap head got blocked with hard water scale perhaps?

Hello Matthew

It's not that uncommon nowadays and doesn't neccessarily indicate a problem.

Possibles:

Airlock. (If hot tap, connect hose between both and open hot at full bore).

If hot tap: Water temp too high.

But most likely is a washer in the process of breaking up.

Sorry if I offended you, was not my intent. But it's taken me 4 years to sort out all the other bodge jobs in this place as well :( Also forgive my presumption about the cold water system, I've never seen it done this way before, but it does cause other issues, like with my power shower etc. (In fact I'm not even sure if ANYthing works of the cold water tank pressure!!)

Nope nothing has been changed or fiddled with by an idiot... it just started happening, so I'll look at the tap washer / lime scale (which is an issue as I had to change the taps last year due to the hot one being unsalvageable)

Mat

It's not unusual to have mains cold everywhere. In the last three places I've lived the only tank fed cold was the shower.