hello, need advice on plumbing situation...no running water in the sink and the wife is getting angry.

I got a new undermount sink which is much bigger and consequently much lower.

My drain line is a lot higher than what I would like and the p trap is consequnetly higher as well.

The drain pipe is long...I know i can cut this but the port that connects the dishwasher would also be cut off. Do you guys know a work around. I can't lower the main drain pipe because it goes horizontally in the back of my cabinets and is connectd at one end to a vent pipe which goes to the roof. I also don't want to add a pump under the sink. Please see attached pictures.

I would start with changing that deep basket drain to one with a more standard depth. I've seen traps that were turned around, so the tall side was the outlet(not legal, but it does work).

Edit- You are aware it's illegal to do your own plumbing in MA?



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Besides changing out the drain basket maybe you could cut the port out and drain the dishwasher in to a separate new trap that you could add to the existing.

Two traps. One for sink and one for the dishwasher.

If I'm not mistaken (I could be as I'm not a pro) that is the (one right way?) right way to do it. At least I've seen it here a bunch in Chicago.

Make sure you are vented.



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I have also seen instances where, because of height limitations, the dishwasher was tapped into the horizontal drain pipe downstream of the trap, so the dishwasher drain is not trapped. While not the recommended way I don't see sewer gases or sewer flies working their way into the dishwasher because the dishwasher drain hose always drops down a bit from the drain pump, runs under the dishwasher to the back and then up and out. So there is a built in trap in the dishwasher drain hose, arising from the way it is routed.

A shallow basket strainer and a direct connect dishwasher tail piece will get you high enough to drop down into your trap.

Before you go through the trouble of solving the problem at hand talk to your wife if she wants a disposer under that sink you are in big trouble!

North Carolina Plumber has nailed it once again...

Sum, the disposer will have to be in the basement.

George, I would still trap it. Especially in a case like above where there is plenty of room. Mine is attached to a hose fitting on top of the trap.

I knew there was something about Chicago code. We can't go in to dishwasher.


City of Chicago code:

When a domestic (private residence) dishwashing machine drain line is connected to the house side of a trap from a sink, the drain from the dishwasher shall be carried up to the underside of the spill rim of the sink. Dishwashing machines shall discharge separately into a trap or tail piece of the kitchen sink and shall not connect to the food waste disposal unit.

If it is done that way, then you MUST have a counter top air vent on the drain line.

Not all have the "rise". In fact most go from the pump directly to the drain line under the sink. And if the DW drain line is connected DIRECTLY to the drain line, it must have the air gap in it.



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Ok, so there won't be a disposer, we have septic.

the wife likes the deep drain, catches all the "stuff"

I already cut the 1 1/2 pipe coming from the 2" Wye so I need to go from there.

I have tried some sch 80 stuff but considering this is under the kitchen sink where everything is put under I don't want anything flimsy.

I was thinking of dropping ~ 6" from the 1 1/2" pipe coming from the wye and attaching sched 40 elbows (2 of them) to some 1 1/2 pipe and attaching that to a 1 1/2 threaded pvc HubX hub p trap. One side of the trap i would need to attach a 1 1/2 trap adapter for my drain pipe. In theory this should work. Everything from the trap to the wye will be filled w water until it is forced into the main drain. Does anyone see an issue with this? Will there be enough pressure from the sink to force the water out to the drain? See diagram of pic.

Look at your picture......It's a huge trap and will back water up into the sink.

Hello,

The diagram is somewhat misleading...it wasn't drawn to scale.

The sink drain is higher than the main drain so I didn't think it could back up, gravity should push the water out, right?

IF we could tell how the pipe was going, we might be able to answer you, but the way it is drawn it looks like the pipe just keeps going higher and higher.

i am not sure I understand what is needed...

From the 1st pic, I just need to lower the trap ~ 6 inches so that I connect the sink pipe drain. I can also cut the pipe drain as well. I was orginally trying compression piping but I can't figure it out whith those fittings. Any ideas is greatly appreciated.

You wouldn't be lowering the trap. You would just be increasing the SIZE of the trap. The only way to lower the trap is to lower the drain exiting the cabinet and the connection to the waste stack it drains in to. The way you have it drawn, the top of the standing water will be ABOVE your dishwasher port on the tail piece. Water will only start to drain once it reaches the bottom of the existing pipe.

If you insist on keeping the deep basket, the tail piece has to be shortened and you lose the dishwasher port.


Then you have to create a second trap for the dishwasher by adding a new "y" before the existing "y". In that new "y" is where the new trap goes. This can be all glued fittings as this trap doesn't need to be adjusted to fit.

This is what I'm talking about. Though I would add a length of pipe vertically in the trap so - sort of like a mini stand pipe. I've seen some left open but I would cap it and use a hose clamp like this one

It's hard to see here, but the sink trap drains in a separate trap in to the wall. The wall pipe is obscured by the copper





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The main drain goes about 8 feet horizonatlly across the back of the cabinets and in the middle it connects to a vent. I don't wan to touch this....

If i don't lower the trap, by removing existing trap and re doing the pvc w other fittings, I can't connect my drain pipe w dishwasher port. It would be an easy cut fix if i didn't have a DW port.

I am thinking of dry fitting everything and openeing the water...i may have some leaks though but I am thinking if I get flow to the waste line i would be good when welded...does this make sense or am i totally off.

I edited with a picture

Excuse the chicken scratch. I live behind Wrigley Field. We were celebrating last night

Nothing you do, short of lowering the whole length of the horizontal drain pipe will be legal. Keep it simple and turn the trap around and trim the tailpiece to fit the short trap leg.

Ps. If the run is 8 feet before the vent you should probably add an air admittance valve somewhere in the mix. It acts like a vent and allows air in the drain so your traps don't get sucked dry. It allows air in but keeps sewer gasses from entering the house.


Not sure of the best location. Easiest would be cut off clean out and add a short pipe and "t" pointed up with a short length of pipe and the valve on top. Install new clean out in the end of the new "t"

But not sure if between two Ys would be better.

My only beef with reversing the trap is they always seem to leak - especially if they get bumped. . My neighbor's dad installed hers backward. It lasted about a month before she had a huge leak.

How about making your own trap with a PVC U-bend? You can make the inlet and outlet legs as long as needed. Use a shielded band clamp to attach to the horizontal pipe, so the trap assembly can be easily removed.

Is there any reason you are married to that deep basket strainer? You are not that far off. If you get a shallow basket strainer then it should fit.

Coming off that tee that you have I would swing the trap back to connect to the back of the wye, and install a CO cover on the branch instead. That will give you more storage room in the sink cabinet and much less awkward to snake from a CO opening that is at least facing somewhat towards where it's convenient to snake.

Sum, I started to write the same post and then read back where the OP explains that his wife is married to that deep basket strainer. IMHO it might be less trouble to find a new wife that can live with a regular strainer. He may wind up pouring a new foundation before it's all said and done... just to keep that deep strainer.

Lol. I've never seen one of those deep baskets but I gotta admit the removable strainer looks cool.

Wouldn't the new trap added for the dishwasher siphon the sink trap dry? The DW discharges with a pump and you don't have a vent in between.



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well, he can give his wife a choice.

Either lose the deep strain basket and go with a shallow one, or he will extend the DW hose to the front of the cabinet, out the cabinet door, up to the sink, and have it discharge into the sink. let her choose.

Well one other thought. May be remove the strain basket, and take it to a machine shop, see if he can have a side hole drilled open, and weld or epoxy in a piece of copper or brass DW connection pipe? Should be doable the only issue is the opened hole may corrode over time depending on what material it is made of.

I just saw this on our sponsor site. A tail piece with a DW wye that's really high up that may work. It's in ABS but you have all slip joints so it doesn't matter.

Yeah, I mentioned up thread he probably should add a vent anyway since he has an 8 foot run to the stack. Maybe between the fittings I proposed.