gurgle in sink when toilet flushed

[moneypenny]

My external soil stack had been reduced to below upstairs window level and an internal air vent fitted, no idea why this was done but never had a problem and it had been like that for years.

Just had a wall hung toilet and washbasin fitted along with new bathroom, everything seemed fine until the bottle trap was fitted to wash basin, now I hear a gurgle in basin everytime the toilet is flushed.

The plumber reinstated the soil stack to above roof level and fed the wash basin waste into the stack. Previously it had been fed along the wall and into the drain, only the toilet went into the stack.

Any suggestions
Thanks

 

[Charnwood]

If not already fitted, an anti-vac or re-sealing bottle trap on the gurgling basin might work and is an easy DIY job.

 

[moneypenny]

Thanks, how would I know which is which the one I have is a cheapo from wicks because the one ordered with the sanitary ware was faulty and the fitter needed one to get on.

 

[moneypenny]

Just had a quick look online and all the anti vac traps are plastic my is a chrome cloakroom basin it would look terrible.

 

[joe-90]

You've got an air restriction somewhere. Is the soil pipe a clear open vent? If not - then make it so.

 

[moneypenny]

thanks joe 9o

The soil pipe extends beyond the fascias and has a plastic mesh cover on I assume this is open vented. Sorry on a learning curve at the moment.
My local building control have told me to get an anti vac bottle trap.
This does seem a fix for poor plumbing I know but my toilet and basin are wall hung and all tiled.

Anti vac traps are available but only in chrome plated plastic.

 

[Charnwood]

Do you have access to any non/chrome pipe:
http://www.wickes.co.uk/invt/424903

 

[joe-90]

When a toilet is flushed it causes a low pressure - partial vacuum behind the water. This should be balanced by air down the vent pipe above the soil pipe - not through your basin waste (Which is a much harder route). Something ain't right.

 

[moneypenny]

Seems to be OK, fitter says the gurgle was because there wasn't as yet any water in the trap, demonstrated it this pm. and as quiet as the grave, well well, panick over for now.

Thanks everyone, have learned something today comments helpful.

 

[joe-90]

FFS.

 

[Charnwood]

No water in basin trap = stench from basin! Was there a stench from the basin, because that pipe was open to the sewage system, almost certainly!

Who fits a basin/bath/sink, leaves the job, then comes back to fill the traps with water the next day?

 

[Nige F]

I always used to fill the basin traps with water that was passed - by me