OT plumbinhg help

[Vahunter]

My son and DIL have double kitchen sinks. They drain in different directions and DO NOT have a common drain pipe visible in the house! Yet both sinks back up at the same time.
Sounds like the clog is outside or under the house where they join together. What is it going to take to fix? Will I need to snake it?

 

[nobands]

Separate traps ?

 

[tcc]

What is it going to take to fix?

 

[Sasquatch Hunter]

It sounds like a job for Resident The Fuge Brain Truth. I would check the Kunder Valve first.

 

[Vahunter]

Separate traps ?

Yes.

 

[PaulinKansas]

The 2 separate pipes reach 1 common drain pipe.

Put enough water in the clogged sinks so that there is about 1" of water in them. Put that rubber/plastic stopper in one sink. Use your plunger to plunge the other sink while holding the stopper in place.. The displaced water has to go somewhere. It's like Boyle's Gas Constant, except you are using a liquid. Anybody knows you can't compress a liquid (like a gas) so something has to give.

 

[JRS]

If there’s a disposal on one- do the same thing Paul said but run the disposal and water while plugging the other sink.

It works well for lesser blockages.

 

[PaulinKansas]

If there’s a disposal on one- do the same thing Paul said but run the disposal and water while plugging the other sink.

It works well for lesser blockages.

If the garbage disposal has an inlet for a dishwasher you may have to remove the discharge hose connection and put a plug in the barbed fitting on the disposer. I think it's 5/8" or 3/4".

 

[JRS]

If the garbage disposal has an inlet for a dishwasher you may have to remove the discharge hose connection and put a plug in the barbed fitting on the disposer. I think it's 5/8" or 3/4".

No backflow preventers in Ks?

 

[PaulinKansas]

No backflow preventers in Ks?

None. You just knock out the metal plug in the disposer and then clamp on the discharge hose from the dishwasher. There might be a backflow valve in the dishwasher, but I'm not very smart.