I replaced a double sink with a single sink and installed a new dishwasher in the kitchen that I am renovating. The new sink won’t drain at all. I can plunge the sink and it will empty but it still won’t drain.
The old sink/old dishwasher combo worked just fine. I had the drywall off and the sink is vented and hasn’t been changed since the house was built in 1979. I made NO modifications to the drain.
I am really stumped. Does switching from a double to a single sink make a difference? Is the new dishwasher causing an air lock? I’m clutching at straws.
Replies
Any chance of a photo, like from a cellphone or the like?
As a guess, the old double had the g/d on one bowl, which then connected across to the the "normal" trap under the other bowl, and the d/w drained into the tailpiece of the g/d.
Now that there's only the one drain point, the possibility of an inadvertent "uphill" condition is middling high. And, this winds up being a major pain in the posterior. You often need to engage in cabinet surgery to go with the plumbing suregery. All of which occurs with a 4-5" bend where human spines don't; while holding up completion of an entire kitchen (or worse yet, the frustrated impatient toe-tapping of SWMBO for taking so [expletive] long . . . )
There was a recent thread on whether two traps were ok, if you care to search for that (some good photos in there, along with a great deal of good solid theory on draining kitchen sinks).
Did you change the depth of the sink when you replaced it?, if so the drain may be too high with the new install. If the dishwasher is installed with a high drain loop or air-gap that should be o.k. Do you have a garbage disposal, new or old? Something has changed, but I can't help without more info.
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"If all else fails, read the directions"
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