What can cause kitchen drain problems?

It depends on your set up. You should only have one trap for both drains. the side without the disposal should come down and connect to a baffle tee, continue down into a trap and connect to the drain. The disposal should connect into the baffle tee. This setup prevents both drains from getting sewer gas. Also check your slope of your pipes you may have backfall. there is a possibility that you rough in on your y is too high.

Answer

I have exactly the same problem, checked trap - clear, snaked 25 ft piping - clear : then I read this! So what should be slope be? 2 sinks are horizontal but diswasher water outlet is higher and attaches to garbage disposal at a lower level. Would I be right in presuming that it should never go below level at disposal to avoid this problem?

Answer

We are also experiencing this very same problem. The water backs into the sink and then back into the dishwasher. We have taken the sink apart numerous times. You can take a garden hose and run it through the open line until the cows come home. Reassemble the parts and it gets stuck again. Shouldn't the disposal/dishwasher line have some sort of backflow device? Could there be two valves - one on the dishwasher and one installed directly into the plubing, prior to when dishwashers came with them? Would this cause the water not to pressurize enough to push through? I can't figure this problem out, but it is about to cause a divorce. Thanks

Answer

I have the same problem. I called a plumber. He ran a snake in the line, checked the flow in the main sewer line. He mumbled something about the venting arrangement and left. He didn't offer to fix it, and he didn't send a bill. I guess I could have a dead critter stuck in the vent. I am going to check that myself and if that is not the case, I'm calling another plumber.

Answer

I relocated my kitchen sink when we remodeled and came up with the same problem, slow drainage. Try an air admittance valve. I got one from lowes.

Answer

A probably installed residential drainage system should never back up. However, if you overload the garbage disposal with lots of fibrous materials, you can plug the drainage piping, especially if the drainage line is not properly installed.

Check the drainage pipe. It should be at least 1 1/2" in diameter. Horizontal drainage piping of 3 inches diameter or less should be installed with a grade of at least ¨ù inch per foot. Use a level or laser to check the grade.

Make sure that the drainage system elbows are long sweep. Elbows with sharp 90 degree turns are susceptible to plugging and should not be used in residential drainage service. Changes in direction shall be made in drainage piping by the use of 45¢ª wyes, long sweeps, short sweeps, quarter, fifth, sixth, eighth, or sixteenth bends, or by a combination of these fittings.

If you have a septic system, check to make sure that the septic system is not full and backing up into the house.

Kitchen sinks may have one or two separate 1 1/2" drains connections into the wall. You may have either one or two traps. Either set-up is acceptable. The drain servicing the garbage disposal should be below the level of the disposal drain to prevent standing water in the disposal.

Run the water when using the disposal to carry away the solids.

Generally, backflow devices are not used for residential plumbing systems as the devices are prone to plugging and failure.

Answer

Horizontal drainage piping of 3 inches diameter or less should be installed with a grade of at least 1/2" inch per foot

Answer

definitely check your vent pipe for obstruction. if you don't have a vent pipe, put a vent pipe or a admittance valve (basically a one way vent) under the sink.

First answer by ID0000000000. Last edit by Flexpvc. Contributor trust: 155 [recommend contributor]. Question popularity: 217 [recommend question]