Sink/Basin overflows

[The Medway Handyman]

Fitted some basin new taps & a new pop up waste today. Apart from checking for plumbing & waste leaks I always check that the overflow is working as well.

Combi boiler, so hot & cold at the same pressure, which was pretty high.

It surprised me how quickly the sink filled up. The overflow simply would not have coped with the flow of water from even one tap on full blast, let alone both. So it would be largely ineffective as an overflow - wouldn't prevent a flood if a tap was accidentally left on.

I wonder if sink & basin designers have thought about the flow rates now that hot water could be at mains pressure?

[Owain]

Aren't sink and bath overflows intended to cope with "waves" slopping about which would otherwise go over the side, and not a tap left running?

After all, if the water supply is that good it's not as though you have to leave the tap running and go away and do something else for ten minutes while it fills up.

Well, maybe you do on some combi installs when filling the bath.

Owain

[Dave Plowman (News)]

Yes - that's why they're smaller. ;-)

[Peter Andrews]

My Doulton pedestal wash basin (correctly installed) is within 3mm of overflowing the front before any water flows down the small overflow, it's so ineffective it may as well not be there!

Peter

[TheScullster]

"The Medway Handyman" wrote

Basins are sold that have no overflows at all. I recently fitted one in the downstairs WC. The waste is fitted with an anti-siphon trap which is slow to discharge, the running water can easily overtake the discharge rate. The kids are now both teenage fortunately (?) and so far no-one's left the taps running :).

Phil

[ARWadworth]

Someone will come along shortly to tell you it is flow not pressure that matters and that a combi will not fill a bath as quickly as a conventional system.

Adam

[ARWadworth]

Looking closer I can see Mr Plowman already has.

Adam

[Dave Plowman (News)]

Predictable me.

Normally dribble would be along to say the solution is two combis but I'd guess he's finally been sectioned.

[ARWadworth]

You wish.

Adam