Air 'ejection' valve wanted !

[robgraham]

Or a suitable solution.

The washing machine is just through the wall from the bath - strictly the end of the bath (that might be necessary info?). The bath couples to the drain pipe just down stream of the washing machine.

The problem is that when the w/m drains it blows air up through the bath trap. I thought to begin with it was an admittance valve problem and air was being sucked down, but no it comes up the way. As far as I'm concerned the w/m drain is all correct.

Can anyone advise please - thanks

Rob

[Ash]

I'd suggest either try to join the washing machine drain after the bath drain or fit a separate drain for the washing machine.

Ash

[Tim W]

robgraham wibbled on Thursday 22 October 2009 21:48

It shouldn't really do that...

How big is the pipe servicing the w/m and the bath - 32 or 40mm?

What joint has been used from the bath to the running pipe? I assume a "tee" - if so, is the sweep of the side inlet correct?

Is there an air break at the washing machine end?

How long is the pipe from the bath to the main stack or hopper?

Photos would be nice of the w/m standpipe and the bath trap + junction - but if not practical, a good text description with details would be helpful.

Cheers

Tim

[robgraham]

Thanks guys - this is a relatively mature set up now (approaching 20 yrs) and I've always just tolerated it, but the AAV query triggered me to ask in case there was an above floor solution.

I can't remember the pipe sizes nor the immediate relationship of the couplings, and I would need to dig the w/m out of its cupboard to photo the stand pipe but it's just the flexible outlet hose stuck into a vertical length of plastic pipe (memory ?). As for the crawling under the floor to do anything, at OF age I'm well past that, and any professional would ask for the floor to be lifted which is not worth doing.

On the basis that the bath trap isn't being sucked out and there's never been any bad odours due to the bubbles, then there being no easy solution, we'll just live with it.

Thanks Rob

[Rick Hughes]

There should be an air-break on a vertical up stand ... i.e your discharge hose hangs in a vertical pipe, but there is an air gap from the end of the pipe to the water in the trap at bottom of pipe .... typically length of standpipe is 700mm giving you at least 550mm air gap.

[robgraham]

I've been to see what there is - the hose hangs in a nominal 40mm vertical pipe, 300mm long which then goes at right angles for100mm through the wall before dropping a further 300mm to disappear through the floor. As there are no nasty smells I think it's reasonable to assume that there's a trap under the floor. I guess the trap is below the 150mm floor joists, so that adds up to your 750mm (perhaps!)

Thanks for answering

Rob

I take it that the hose in the vertical pipe is the 'air break'?.