discovered shower drains slow because of Ubend trap on basin

[dingletastic]

Hi all, been reading these forums for about the last 12 months hoping to find out why my shower drains very slowly, and has done since it was installed by a plumber who just shrugged his shoulders when i told him about it.

after reading various threads i thought it was to do with the length and fall of wast pipe not being correct, finally decided to remove the basin last night so i could get under the shower to take a look (its an ensuite so space is tight), then a eureka moment well it was for me i'm not that handy.

when the ubend is connected to the basin waste and has water in it the shower drains slowly, if i take the ubend of or just empty the water and put it back on the shower drains beautifully. being an general geek i thought this is obviously something to do with air pressure, went out today and bought an anti syphon bottle trap, tried it tonight and have exactly the same issue.

sorry for waffing on but trying to explain the best i can.

Thanks for reading hope someone shed some light.

Dingletastic

 

[TicklyT]

What's the betting there's a waste pipe runing uphill, with the basin waste teed into a high point?

An anti-syphon trap will allow air into a pipe to relieve a partial vacuum, but it won't let air out of the pipe if it airlocks because the fall is the wrong way.

 

[dingletastic]

Thanks for that, i'll take a look, the basin is at the end of the waste run if you know what i mean, the waste water from the basin has to run passed the junction with the shower, not sure if that makes a difference.

Thanks again.

 

[bengasman]

Bath or shower waste needs a fall of about 4% to drain fast, 2% as an absolute minimum.
Half the plumbers in this country seem to think that 4% means 4 mm over the length of the bathroom.

Does this look like the guy that did the work? View media item 15469

 

[Nige F]

Fit a Hep V O waste valve instead of basin trap If it don`t work , message me and I`ll buy it off you. You`ll have to pay the postage tho`. How (is that ) Kimosabe ?

 

[JayJay1978]

my shower drains very slowly, and has done since it was installed by a plumber who just shrugged his shoulders when i told him about it.

When he asked "where's my money" you should have shrugged your shoulders.

 

[dingletastic]

hi thanks for your reply's, i do have a HepVo on order but ordered it for the shower so ordered a 40mm , i will try to return it and get a 32mm and attach it to the basin. your quite right about the cowboy, he went bankrupt not long after surprise surprise.