Unusual washer standpipe. pls help

[boomny]

Hello and thank you in advance to any guidance and advice you can provide on this...

The house is ~50 yrs old . Up untill recently the utility room located in the basement(below grade) had old-ish type top-load washer. It was draining fine. We recently replaced the washer with the bran new front loader. The standpipe which im attaching a picture of below overflows whenever we do a large load spurting water out of 1" inlet pipe. Judging by the configuration of the standpipe my thinking is that it's not the diameter of the standpipe itself that's unable to cope with additional flow but rather the ptrap placement and its inlet pipe which is smaller in diameter. Ptrap seems to be placed unusually high. The only thing i noticed when i removed the old exhaust hose was that it was really "tight" in the inlet pipe making it sort of "closed system." The new exhaust hose fits rather loosely. Would it be advisable to install one of those compression adapters(DESANCO fittings) onto an 1" inlet pipe connecting washer hose to that which would make it "close system"? The standpipe has been draino-ed and snaked and as mentioned earlier there are no flow issues with smaller loads. Are there any changes I can make to the stand-pipe to accomodate additional flow?
My wife advocates installing utility sink to alleviate drainage problems. Could i simply use standpipe as a rough-in for utility sink connection? Then we could simply drop the washer hose into the sink and let the excess water drain in its own pace. If i go that route, would the sink have to be vented? could i use one of those AAVs/cheater valves as running a separate vent to the roof seems really daunting and beyond something i can do on my own.

Any help is greatly appreciated!
J

 

[Gary Swart]

Wow! No wonder you are having problems. You got by with the old washer because it did not dump water as fast as the new one, but your drain system is really all wrong. You have an S trap and no vent. I think the simplest way to straighten this out is to start from the bottom and work up. You need a P trap located near the floor and a vent pipe. To avoid another S trap, you must have a vent after the P trap and prior to the drain turning down again. In other words, you can't go down, up, and down again without a vent. The S trap you have would be a P trap is the "clean out" continued up as a vent. However, that still would be wrong, because the trap is too high in the standpipe. The standpipe should be higher as well. Then the washer drain hose should not be tightly connected to the standpipe. The hook end of the hose just should hang into the top of the stand pipe. I think you can fix this problem fairly easily.

 

[Sponsor]

 

[boomny]

Thank you for replying!
So would this be acceptable? From what I've been able to ascertain AAVs are allowed in NJ(http://www.mpesnj.com/air-admittance-valves-allowed.html)

 

[boomny]

Thank you for replying!
So would this be acceptable? From what I've been able to ascertain AAVs are allowed in NJ(http://www.mpesnj.com/air-admittance-valves-allowed.html)View attachment 20017

Mistake on the pic - min length should be 30"
height 30-48†, trap <= 12†above floor.

Does that seem correct?

 

[WJcandee]

I think you should have 2" on the drain, not 1".

Regardless, have a look at the tenth page of here for some guidance (and look around the rest of it because it's very informative and referenced a lot on this forum): Helpful Plumbing Hints for Residential Construction by Bert Polk Plumbing Inspector Lincoln County

 

[Cacher_Chick]

What you have drawn will work.

The standpipe and trap must be 2", and I would put the AAV up as high as possible. The AAV must be left accessible, as they do need to be replaced.

A washer drain hose should always have an air gap between the hose and the standpipe. It should not have a watertight connection.

 

[hj]

If it is overflowing because of "positive pressure" due to the lack of a vent and downstream problems, then an AAV will do exactly the same thing because it will NOT relieve positive pressures.

 

[Enosez]

Why not plumb a laundry sink and dump the washing machine into it.

 

[Cacher_Chick]

Why not plumb a laundry sink and dump the washing machine into it.

It would not matter, as a sink would still require a proper trap & vent.

 

[boomny]

If it is overflowing because of "positive pressure" due to the lack of a vent and downstream problems, then an AAV will do exactly the same thing because it will NOT relieve positive pressures.

So the only way to rectify this would be to run the vent line to the roof or connect to the existing vent line on the first floor, correct? That may be a problem as there are no vent lines going from basement to the first floor. Are there any other ways to run the vent? thnx!

 

[Cacher_Chick]

As long as pitch is maintained, the vent can be run to a location in the basement where it can turn up through an interior wall and up through the roof. While this would be ideal, you might want to try the AAV first to see how that works.

 

[Enosez]

It would not matter, as a sink would still require a proper trap & vent.

Isnt an AAV not allowed on a washing machine standpipe.
Couldnt he use the AAV to vent a utility sink which could catch the washing machine.