I recently moved to a new townhouse where I’m slowly getting used to the space’s quirks. This morning I noticed a substantial amount of water (perhaps a gallon?) under the kitchen sink for no apparent reason. I should note that there is a garbage disposal connected to this sink.
The only unusual thing I did today was fill the sink with soapy water to do the dishes. Typically I would just wash a few dishes at a time and thus not plug the sink. My question is if there is a significant likelihood that removing the plug and emptying a large sink full of water at once could conceivably cause leaking when under normal circumstances there is none.
Yes. Leakage around the disposal. Normal use may not have the water level rise that high inside the disposal. Also releasing that much water can shake the disposal allowing it to leak anywhere. If there’s a dishwasher inlet in the disposal the hose may not be tightly connected, or if there’s no dishwasher connected the cap or plug in the inlet may be loose.
Just to be clear, what you did is unlikely to have CAUSED a leak, in the sense that it broke something and now it’s got a leak that wasn’t there before. What is true is that a small leak might not be noticed in normal use, but become very apparent when the sink is full and then drained. The large amount of water increases the pressure in the pipes and forces more water out of what would otherwise be a minor leak. Filling the sink like that is actually the recommended way to test for leaks after doing a repair. It’s not necessarily related to the disposal; it could be any place in the drain pipes. If you want to determine where the leak is, dry all the pipes, spread newspaper under them, and repeat your “experiment” – fill the sink then let it drain. You’ll see where the water is dripping onto the paper. Although if there was really a gallon of leakage, you may want to first try with just a few inches of water in the sink.
Does the sink have an ‘overflow’ outlet? (The hole that prevents the sink from overflowing if a tap is left running with the plug in).
Did you fill the sink above the level of this overflow?
The overflow normally has a pipe that connects straight back into the sink drain (underneath the bench). It may have disconnected.
As others noted, it probably won’t cause a leak (unless the weight of the water cracked or shifted something), but it might reveal one. When I install a sink or redo drain plumbing after I run some water, the next thing I do is fill it all the way up and let it all go down at once. That often times shows me leaks that I wouldn’t have otherwise noticed right away. When you’re just running water it’s trickling across the bottom of the pipes, but a big surge like that will (more or less) fill the pipes so a leak that’s near the top of one of the connections might start dripping water.
Also, you said it was a gallon, that’s a lot of water, another place that can leak when you fill it with water that might not otherwise be a problem is where the drain basket connects to the sink (the connection you make with plumber’s putty). The weight of all that water sitting on it can push it through, but when it’s just running over the top of it, it’s not a problem.
If I were you, I’d fill it back up and check under the sink with a flash light, that much water shouldn’t be hard to spot the source of.
BTW, if you or anyone you know is at all handy, drain pipes are sometimes very easy to repair. There’s no soldering or special tools involved (although a Channel-Lock sometimes helps); usually it’s all held together with compression fittings, sometimes hand-tightened. It’s quite possible your problem is just that one of those fittings is loose and needs to be tightened.