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Anti-siphon bottle trap issue

Hi All,

I have fitted a new bathroom sink and the run to the main waste is around 4m. It gurgles so decided to switch the existing bottle trap for an anti-siphon one.

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What I thought would be a 2 minute job...... The anti-siphon one is much deeper than the current one and unfortunately the drawer of the cupboard under the sink hits it - it is probably about 10mm too deep. I have looked around the web and it seems like they are all the same depth (approx 120mm from the centre of the waste pipe to the bottom). So to fix the issue I have the following thoughts although none really good...

  1. The bottom of the 2 traps look like they are interchangeable so I could swap them. However the bigger one has a plastic pipe which goes down the centre of the bottle bit. I suspect this is key to the anti siphon bit. I could cut this to enable the shorter one to fit but suspect I may be back to gurgling :)
  2. I cut 10mm off the chrome waste thread to lift the lot up. From a waste perspective that would probably work but the chrome waste is silicone in so would be a bit of a pain and also cutting it smooth and straight to ensure a good seal would be difficult
  3. Fit an inline anti-siphon valve and use the original trap. This is a bit of a pain so would ideally not go down the route.

Anyone have any bright ideas?

thanks

Lee.

Reply to
Lee Nowell
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Surely it is only the back end of the drawer that catches the trap, can you not cut out a 10mm deep notch wide enough to go round the bottle trap?

Richard

Reply to
Tricky Dicky

If only life were that simple :) The drawer is a bit weird and it has a bar that goes across the back which rotates as you move the drawer in and out. Not entirely sure what it does but it would have to go as well.

Reply to
Lee Nowell

That's what I did when I redid bathrooms a little while back, just fitting a tee into the waste pipe, and stuck an AAV on that, and then used a normal trap on the basins.

Reply to
John Rumm

The critical thing is the depth of water in the trap. Nothing else matters.

Reply to
harry

Put the original trap back, you'll find the anti-syphon one gurgles too. If you look at the new one you'll notice you can convert the original by tying a little bit of tube in the right place.

Often gurgling is caused by problems with the downstream drainage.

NT

Reply to
tabbypurr

Just changed the bath and basin traps (one v. shallow; one bottle) for waterless ones. McAlpine MacTrap for the bath - that's outside (tested winter before last (just over a year ago) and it desn't freeze. HepVO for the basin, direct on the basin, not too satisfied, so that'll go outside eventually. The basin one is a long way down (about 12" or so to bottome of bend) but when I move it there'll be only the elbow below the outlet.

Reply to
PeterC

Can't,you run a siphon break connection back to a higher point in the stack?

Reply to
Cynic

Hi All

Sorry for the delay in replying. Looks like my only option is to put an anti-siphon valve inline somewhere.

My setup is as follows. It is an upstairs bathroom and the sink waste goes in a stud wall, down to below the floor then essentially a straight run of around 4 or 5m and then into a vertical soil stack down into the drain. The only viable place to add the anti siphon valve is on the straight run. If absolutely necessary I could put it next to the trap but access is difficult and I don't believe the pipe coming out of the wall is long enough to fit valve then trap.

I have a few questions

  1. Is an anti siphon valve likely to solve the gurgling problem?
  2. Will fitting it on the straight run work ok? If so assume as close to the trap as possible as opposed to the soil stack end?

Thanks

Lee.

Reply to
Lee Nowell

After investigation into what the hell anti-syphon means, it doesn't look any deeper than other traps from the same maker. Have you considered a waterless trap?

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Reply to
Dave W

Anti syphon does not mean it needs to be any deeper - it just needs an AAV on the sewer side of the water trap.

Reply to
John Rumm

Quiet a few years ago, when I did our bathroom, I used HepVO for basin, bath and basin in downstairs WC immediately below.

At least ten years without any problems other than once or twice having to open it up due to lots of long dark hair. Not mine. Having three of them meant that they acted as air admittance for each other even if the bath was in use.

I also used good quality flexible waste pipe (was that Hepworths as well? not sure). I'd do exactly the same again if refitting another bathroom.

Reply to
polygonum_on_google

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