Hissing Tap

[chucklechops]

Hello,

I've noticed that my bathroom basin tap has started hissing constantly while it's turned off. It actually sounds like water is constantly flowing through the tap. There is a tiny, constant dribble of water from the top of the tap which has been there since I installed it a couple of months ago and basically put down to bad design. I'm 100% sure that the dribble is nowhere near enough to explain the hissing noise.

The tap is one of these monstrosities:

I have no idea what's going on inside these sorts of taps. My theory is that some kind of valve inside the tap is worn or faulty and water is flowing from the cold pipe into the hot pipe. I'm also hoping this will explain why my cistern is overflowing.

Has anyone encountered this sort of thing before? What else could cause a tap to hiss?

Cheers in advance.

 

[Bahco]

If the tap is hissing there is obviously air present in the supply /possible airlock.
Do a search on airlocks on this forum.
As for your cistern overflowing you need to address this by changing ball valve or adjusting arm down by bending until water level is 1in below overflow outlet

 

[chucklechops]

If the tap is hissing there is obviously air present in the supply /possible airlock.
Do a search on airlocks on this forum.
As for your cistern overflowing you need to address this by changing ball valve or adjusting arm down by bending until water level is 1in below overflow outlet

Cheers for the reply,
The hissing definately isn't air. It's hard to describe but it's actually the whistling sound you hear when you have water running through a pipe, and it's coming from inside the fitting. You'd know what I mean if you heard it. Also, I'd have thought that if air was coming up to the tap I'd expect to have some spluttering when the tap's turned on, yes? I've already replaced the ball valve on the cistern which didn't help.

A couple of hours ago the cistern started to overflow so I cut the cold supply to the tap, the hissing stopped and the overflow stopped a minute or two later and hasn't happened since.

I'm now pretty certain that water is flowing from the cold into the hot supply through this faulty tap, feeding back into the cylinder and draining into the cistern through the vent pipe causing it to overflow.

Sounds a bit improbable but it's the best explanation I can see. I'm going to wait a couple of days to see if there's any more overflow and then take the tap back to B&Q, thank them for flooding my kitchen and ask really politely for a replacement.

All the best.

 

[ChrisR]

The cold mains pushes the tank fed hot back into the coldcistern. Common problem with cheap taps, BUT any competent installer would know that you HAVE to have double check valves in the supply to the tap to stop just this problem. Don't bother arguing, just do it right.