Dual flow mixer tap - siphoning effect

nande2000

Hi,
I've just had a new kitchen put in and have had a traditional dual flow mixer tap installed to complement a Belfast sink.

When I use the cold water (hot water is fine) and then 'close' the tap the water continues to run on for another couple of seconds and drip for a while afterwards. I'm understandably not happy with this as over time it will waste water.

I've contacted the manufacturer (Pegler Yorkshire) and they have sent a replacement ceramic washer, but it has had no effect. They are now saying this run on with cold water is normal and is due to the siphoning effect. It is only happening with the cold because with dual flow taps there are two elements, one next to the wall of the spout (cold) and one in the centre (hot), thus the hot doesnt siphon and the cold can.

They are saying my only option if I cant live with it is to switch to a monobloc mixer tap. Any plumbers have an opinion if this is a load of nonsense ? Seems crazy in the modern era of efficiency that this is an acceptable design for a tap.

southcoastrgi

pic or link to the tap ?

anotherbaldrick

I don't think you are looking at anything unusual, the riser tube of the mixer is bifurcated, it has a smaller inner pipe ( the hot water) surrounded by an outer ( the cold ) tube. The hot responds more quickly while the cold because of the larger cross section and volume area has a trail off and drip for a few seconds. So long as the tap stops dripping after say 10 seconds everything is normal and it is just the trail off . For your own interest when you have shut the cold off, turn the swivel riser vigorously from side to side and you will see the retained content shake out.

Ectophile

Can I suggest turning the tap off 2 seconds before whatever you're filling is full?

If the tap is an inverted J shape, then it's pretty much inevitable that this will happen. When you turn the tap off, the pipe is full of water, and it's going to want to fall out of the tap when you turn it off.

nande2000

I think there is air getting in somewhere. It runs for a good 6 seconds after being turned off and drips for a least a further 30. I have 2 other dual flow mixers in the house and neither have this problem. A modern tap should not do this, end of.

anotherbaldrick

nande2000 wrote: »

I think there is air getting in somewhere. It runs for a good 6 seconds after being turned off and drips for a least a further 30. I have 2 other dual flow mixers in the house and neither have this problem. A modern tap should not do this, end of.

You still have not posted a link or pic of the particular tap we are talking about. If you seriously want some definitive advice give us a clue !

nande2000

Its this one. http://pegleryorkshire.co.uk/EN/ProductDetails?Id=9693ba8e-1d83-421a-be26-a66f72bcd703&Rid=dc26433b-a2d1-4b98-b1b7-6e71063f7b46

Ruski

I fitted the exact same tap a couple of months back and it does the same as you are describing - I'm afraid that you can't break the laws of physics, a tap with this much 'overhang' is always going to siphon.

Take that one off and flog it if it upsets you and then fit this:

http://pegleryorkshire.co.uk/EN/ProductDetails?Id=fabd76a2-89ae-472b-a865-5f16049669e9&Rid=dc26433b-a2d1-4b98-b1b7-6e71063f7b46

This will not have the same issues.

HTH

Russ