Water backs up into second sink when disposer ran

[sgregg003]

I have a couple questions, when trying to fix issue #1, I created a new one.

1). In my kitchen I have a two sink setup, one sink has a garbage disposal. When the garbage disposal is ran the water backs up into my other sink before finally draining out. When the disposer is not in use the sink drains fine. The setup below the sink is a center outlet drain going through a diverter "T" into the pipe leading to the trap. I took this apart this evening and replaced the diverter "T", and made sure the pipes were level, but still the same issue. Any ideas to stop this would be greatly appreciated.

2). When trying to repair the above issue , all these parts are chrome plated brass 1 1/2 inch. I was trying to loosen the coupling on the waste arm that goes toward the wall, but instead of the coupling coming loose the whole piece came out. The coupling from the waste arm went into a piece that was threaded on one end, and reduced in diameter at the other other end to fit into another pipe coming from the wall(no coupling or anything). When I ran the disposer to test it, it leaked at the point where the reduced end went into the pipe coming from the wall. Where the pipe slides inside the one coming from the wall there are a couple drops of a hard gray substance in a couple places, which I have no idea what it is, but may have been some kind of sealant maybe? Any idea what I can do to stop this leak, and what I would call the pipe that slide inside the other pipe in the wall(I think it may need to be replaced).

Any assistance would be greatly appreciated.

Thanks

S. Gregg

[inspector808]

If this has not happened before, and has just suddenly started to occur, perhaps you have a partially blocked drain.

If this has been an ongoing concern, I would think the water being forced out by the disposal would typically travel in a straight path rather than taking a sharp 90 degree turn at the center mounted tee, thus allowing the drain water to wind up in the sink bowl before draining out.

Perhaps reconfiguring the drain so that the centered tee is relocated below the sink bowl may help you better control the water's path. Most home centers have what you need to do this, ask for a disposal drain kit.

As for the sealant, typically a chrome drain assembly has a nut which when tightened to the threads at the wall will compress a rubber-like ferrule, creating a leak free joint. Sounds like the ferrule and/or nut went missing and the joint was improperly sealed with some kind of caulking.

[Scottpat]

The drain line from the disposal should connect to the line coming from the sink without the disposal. A directional fitting with a baffle inside of it will direct the water down the line and keep it from backing up in the sink. A trap is then below the connection point. This is the best method.

The "T" configuration can still be used but you need to install a directional "T" with a baffle in it. You can still get some backup simply due to the sinks and drain lines all being the same, but it should not be as bad.

As for the leak it sounds like a compression fitting that is messed up.

You might want to call a qualified plumber, they should be able to take care of this in about an hour or less.

You do not want to use any sealants! This is not how you repair leaks.

[inspector808]

The "T" configuration can still be used but you need to install a directional "T" with a baffle in it. You can still get some backup simply due to the sinks and drain lines all being the same, but it should not be as bad.

I believe S. Gregg stated he had already "replaced the diverter T", I assume this would mean one with a baffle.

If a Wye is used at the wall, then the sink and the disposal can each drain independently without the use of a Tee. Of course each would need its own trap.

Like Scott said. This is an easy fix for a plumber, when in doubt, call a pro!

[Brandon Whitmore]

If a Wye is used at the wall, then the sink and the disposal can each drain independently without the use of a Tee. Of course each would need its own trap.

2 traps are typically not allowed to be installed on a single arm. UPC-1001.1 / IRC P3201.6 for example.

[inspector808]

If a Wye is used at the wall, then the sink and the disposal can each drain independently without the use of a Tee. Of course each would need its own trap.

2 traps are typically not allowed to be installed on a single arm. UPC-1001.1 / IRC P3201.6 for example.

Interesting. I can't count how many times I have installed a wye with 2 traps below the kitchen sink in order to connect the sink and disposal.

I have even used a double wye with 3 traps to connect three compartment sinks in restaurants.

Never knew it was against code to do that, good to know! Yet another reason to participate here.

Thanks!

[plummen]

double traps under a sink arent common around here either,double the things to worry about in my book anyway.

commercial sink drains are generally routed to a floor sink with a strainer,not directly into sewer.many places also require a grease interceptor for commercial kitchens []

[inspector808]

Look what I found during my inspection today. Guess I am not the only one to have "illegally" used a wye..[:-dunce]

Download Attachment: Wye under kitchen.jpg

247.13 KB

[plummen]

why would anybody go to all that trouble and expense? plus if the clog is in the stack both sinks will back up making it harder to diagnose

[RobC]

Look what I found during my inspection today. Guess I am not the only one to have "illegally" used a wye..[:-dunce]

Download Attachment: Wye under kitchen.jpg

247.13 KB

.......and a missing clean out