Sounds silly, but seriously…is a dishwasher drain strictly by gravity flow? Or, does it only drain when today’s dishwashers tell it to? In other words, are the controls tied into a valve or condensate pump, perhaps? It sounds like my dishwasher is not draining, and upon opening the door, there is water in the bottom. The dishwasher was making a periodic fizzing or hissing noise, so I cut off the circuit breaker. (Not sure if the dish detergent could have been making the fizzing (or, hissing) noise while still in contact with hot water?) I’m a little skiddish about poking around in something fizzing / hissing at me!
I should add that it was not draining with the power on. However, it seems this dishawasher makes a “click” (like a solenoid valve opening) before draining occurs. Or, that’s what’s it sounds like is happening inside. (FYI: This is a low-end Amana installed maybe 2-3 years ago.)
No, it’s not just gravity. There’s a pump that empties the dishwasher at appropriate times. Often, the outlet of drain hose is attached to the kitchen sink drain before the elbow, which is above the bottom of the dishwasher, so relying strictly on gravity isn’t an option.
There are a number of things that could be wrong in your case – stuck or burned out pump, loose wire, bad control circuitry. In the case of our last dishwasher, it was the control panel, and a replacement was 75% of the cost of new dishwasher from a discount shop for a do-it-yourself installation. Guess who got a new dishwasher.
It might also be that the washer’s drain is simply clogged.
There should be a basket or a screen where it drains. Check to see if it has gunk in it and do the nasty job of removing said gunk to see if it can drain. The hissing sound you were hearing may have been the drain pump running dry because it couldn’t move water through a clogged screen.
You will have to try runnining it again after due logging. It probably needs to pump the water out. Gravity alone won’t do it.
You should check first that the drain isn’t physically blocked. I remember one occasion where a dishwasher was not draining. On lifting out the drain filter assembly in the floor of the dishwasher, I discovered a small piece of glass (part of a cheap wine glass) sitting neatly on top of the drain hole, effectively blocking the drain.
Your drains inside the dishwasher may be clogged. Remove the bottom rack, take out any left over water, and try to locate the drains. There could be something like a piece of plastic wrap covering a drain hole. Some dishwashers have a filter over the drain that needs periodic cleaning. Otherwise, the pump or control circuitry has a problem, or the hose or the drain it’s connected to is clogged. Possibly the fizzing was due to the heating element for drying coming on while there was water in the bottom. I’ve never heard of a dishwasher that has a gravity drain. Maybe those little countertop things do.
This is unlikely to be your problem but if it is it’s a cheap fix. There should be an “Air Gap” located next to the faucet on your sink. This might be clogged and preventing your dishwasher from draining. Usually, there is a cover that you remove by pulling upwards and then a cap that you unscrew. Remove any crud that may be blocking this drain. Everyone with a dishwasher should check the air gap every six months or year.
Not all dishwashers have them; it depends on how the drain line is connected. If it’s above the trap or if it passes through the garbage disposal, the air gap is not needed. I don’t have one on mine, for example.
The dishwasher should always connect on the house side of the trap. If it connected on the other side, sewer gasses would come in through the air gap or (if you don’t have one) the dishwasher. That would be bad.
Having said that, most dishwashers have some sort of air gap. They serve a few purposes. The main one being that they break the vacuum so that when the dishwasher stops pumping and the water at the high point wants to fall back down it doesn’t create a siphon and start pulling water out of your drain. If, for example, your disposal was full or something was improperly mounted, your dirty drain water would fill up your dishwasher. There’s a few other reasons, but that’s the big one. For this reason, you’ll sometimes see them called “Anti-siphon valve/gaps”
Chefguy, I assume you’ve nosed around at some point, but from time to time, they get mounted under the sink, as high as possible.
Also, if you don’t have one, the drain line should be looped (and fixed) as high as you can get it under the sink before coming back down and connecting to the drain. If it just goes straight uphill from the dishwasher to the drain, drain water from your sink has no reason not to flow down it.
My daughter’s diswasher wasn’t emptying so pulled it out yesterday, removed the drain pump and there was a plastic clip preventing the impeller from rotating.
There are guides on YouTube that show you how to do simple tasks like this.
Air gaps are needed, otherwise it is a cross-connection and there is the possibility for contamination between the drain and the dishwasher. Local codes may not require the air gap, but this does not mean that the cross connection doesn’t exist. It just means you have crappy codes.
As for the OP, some dishwashers have grinders the grind up any food that collects in the dishwasher. I’d guess that a low end dishwasher probably doesn’t have one. In that case, there is probably a filter or screen that you need to clean out manually.
I’ve replaced the dishwasher a couple of times. In each case it came with a long flexible hose. The instructions were quite clear to hang the middle of the hose a certain minimum distance up to prevent backflow. On the 2nd one, there was a hook on the side to hand a cord around the hose to hold it up properly. No way could gravity be used, nor should it. There’s definitely a pump.
Does it run at all? I think generally there is 1 pump in a dishwasher, and a valve that directs the water to the Drain or to the Spray Devices. Or maybe it turns one direction to drain and the opposite direction to spray. If it runs but just doesn’t drain, I’d suspect the pump is OK, and the problem is a clog or control problem.
Are you sure the hissing noise isn’t the water filling up the machine?
Thanks all. It’s fine. My wife thought the dishwasher was making funny noises. That’s where this all started. Not sure what she heard. The fizzing, I believe, was the dish detergent in mid-mix, mixng with hot water. As for the drain, the cancel button allowed the dishwasher to remember how to drain itself. All is well!
Is it a GE dishwasher? Many of them, plus a few other brands using the same components) have a diverter check valve that’s easily replaceable which can cause a dishwasher to not drain. Look inside the machine towards the back. If there’s a screen there, look for a little valve. Here’s a picture of what to look for: