Waste 'P' / 'S' trap or Bottle Trap - which is quietest?

JohnB47

A future project I have in mind is to redo the waste piping under our kitchen sink.

Currently the sink and the washing machine outputs both go through the one 'P' trap (or maybe 'S' Trap, I can't remember and I'd need to dismantle stuff to find out) then along a single pipe out to the gully outside. When the washing machine empties, there is a loud glug glugging sound.

Prior to this, before our kitchen was redone, there were separate 'P' (or 'S') traps and separate waste pipes all the way out to the gully. This was much quieter.

So I know what to do (I've done this sort of thing before) but what I'm wondering is if a Bottle Trap is quieter than a traditional 'P' or 'S' trap arrangement. There is room enough for either.

Any thoughts welcomed.

z1a

Never really noticed noise from any.

nofoollikeold

1. Bottle traps tend to block more easily, and are not the best for solution for a kitchen sink.
2. The washing machine emptying shouldn't make a "glugging" sound. Has the washing machine waste been run correctly? Should be run up to just under work top level, then down and almost immediately into the spigot on the input side of the trap.

EssexExile

Go back to separate waste pipes for sink & washing machine.

JohnB47

nofoollikeold wrote: »

1. Bottle traps tend to block more easily, and are not the best for solution for a kitchen sink.
2. The washing machine emptying shouldn't make a "glugging" sound. Has the washing machine waste been run correctly? Should be run up to just under work top level, then down and almost immediately into the spigot on the input side of the trap.

Yes, everything has been done properly.

I think the washing machine waste going down the combined trap creates a turbulence in the trap water and this resonates in the stainless steel basin above (there's a small side basin too, which has it's own pipe going into the one trap). So the sink is acting like a sort of sound box or amplifier to the water being pulled down and refilled as the washing machine empties.

Then again, I discovered our bathroom basin making the same noise and that seem to have been cured by my rodding out the pipes. (not using one of those cleaner liquids, I mean actually using a flexible rod with a sponge attachment at the end to really clean out the pipes). So maybe that's part of the problem. I'll sort that at the same time redoing the traps.

Anyway, question answered - if a bottle trap clogs easily and isn't quieter, then two 'S' Traps it is.

Thanks for the help.

Jonesya

Why not just move the washing machine to a standard appliance trap? These are a P trap but with a tall riser pipe, the machine waste hose is pushed well down the riser and you don't get much noticeable noise.

I think the noise you're hearing is probably because the waste water from the machine is pumped out at a high rate, hitting the water in the trap below the open sink waste, so the noise has a direct path up into the kitchen.

JohnB47

Jonesya wrote: »

Why not just move the washing machine to a standard appliance trap? These are a P trap but with a tall riser pipe, the machine waste hose is pushed well down the riser and you don't get much noticeable noise.

I think the noise you're hearing is probably because the waste water from the machine is pumped out at a high rate, hitting the water in the trap below the open sink waste, so the noise has a direct path up into the kitchen.

I agree with you on both points. Cheers.

cyclonebri1

In any scenario the deeper the trap the quieter. A generalisation I know but holds water, (I'll get mi coat).

southcoastrgi

It would be unusual to use s traps under a sink the normal trap to use would be a p trap

Slinky

We had a bottle trap on our bathroom basin and it was an absolute curse. Kept blocking. Managed to get a plumber to replace it with a simple S shaped trap and no problems since. Would not have a bottle trap again on anything where an alternative solution was possible.


ETA there's no noticeable difference in noise.

JohnB47

Thanks folks. Here is a pic of my current arrangement. Yes that's a P trap but it becomes an S because of the pipework after.

I'll be undoing this lot and will have two P traps, one for the two white pipes coming down from the top (two basin sink) and the other for the grey pipe on the right (washing machine outlet). You can see the screw holes and marking on the wall where the original two trap arrangement used to be.

https://i.postimg.cc/Ss6nq7wb/IMG-20161210-112415.jpg