Think I may need a new Ubend/trap

cubix

From time to time we get drain smell coming up through the plug hole in the wash hand basins upstairs when taps are run which in turn is breaking the ubend water seal. Each soil stack they are attatched to are vented, so am wondering what trap can I use to replace the standard ones or is there something else at work??.

Thanks

tombull82

Try putting dilute disinfectant down the sink to see if that kills the smell.
If not probably best off looking into fitting a "bottle trap" <-- to replace the U bend system you have

Davy

How far away is the soil stack though? Even though its vented, it can pull the water from the trap if its too far away and probably why its happening. A soloution can be to install a boss, and run an 1"1/2 up into the attic to a vent tile

cubix

Cheers lads, will have to take a photo of ubend alredy in place as I think it may be a type of bottle trap. Sewer stack is only about 6 feet away but dont think this is the issue. The smell only really happens when you run the tap in the sink which is breaking the water seal.

Outkast_IRE

do a search for a mcalpine resealing bottle trap these may suit your needs , its worth looking at anyway

Buford T Justice

If you have access to the waste pipes, you could also fit a non return valve on the pipe before it hits the soil stack

Sparkpea

sounds to me like a shallow trap/bottle trap has been fitted and you need a 'deep seal' trap. A deep seal trap should be fitted to any bath/whb etc. that is piped directly into the soil stack rather than an outside drain/gulley. When a toilet is flushed it can suck some of the water out of shallow traps leaving it unsealed and smells can escape. Normally fitting a deep seal trap cures this. A deep seal trap has a bigger U bend and the water cant be sucked out of it the same when a toilet is flushed. Most plumbers seem to install shallow traps and after a while people find the same problem.

Another option is using a hep2o self sealing trap, or a 'condom trap' as some people call it. Its basically has a long piece of rubber down the middle of it that seals after water is passed through it. You could pay around £10 for one whereas the mcalpine deep seal trap may only be about £3. In some cases on the horizontal when I can't get a deep seal trap on I would use the hep2o one for example on commerical cheese counter type fridge machines.

Davy

I like the hepo ones, find them great. Fits better behind a pedestal too

Sparkpea

prefer these myself for peds

cubix

Thanks lads, appreciate all the replies. As mentioned there was a type of bottle trap fitted, so I took it apart and gave it a good cleaning. Hopefully this will solve the problem.