Dishwasher "belches"

[andyvh1959]

My diswasher is a older KitchenAid, still works great and I can service it myself. Its to the left of the sink which is set up like an island sink plumbing wise. So the sink drain/vent underneath has the triple risers for the vent system. About two years ago I rebuilt the rotted drain plumbing underneath that was actually caused by a clogged vent system. After fixing the rotted black pipe drain system, I also cleared the vent system so the kitchen sink and dishwasher actualy "breathe" like they should after I bought this house back in 2002.

As part of my kitchen remodel I installed a large deep double basin apron style sink. To get that installed I removed the garbage disposal since I never liked the damn thing anyway. My ex would cram all sorts of food waste stuffs into the garbage disposal. Usually no bog deal but in my house the kitchen/diswasher drain system has a near 20' run through the floor before getting to the darin stack in the basement.

All good now, everything works, drains, etc. Except every now and then the dishawasher makes a very obvious "ggggrrrronnnn" sound like a belch when it changes cycles. The dishwasher drain used to be routed through the garbage disposal, but now it connects directly to the drain point that the garbage disposal connected to. Makes me wonder if the garbage disposal acted like a muffler or resonator that let it breathe better. Or perhaps, the dishwasher drain is not totally effective and the dishwasher belches as it tries to force the draining action.

 

[mike93lx]

My diswasher is a older KitchenAid, still works great and I can service it myself. Its to the left of the sink which is set up like an island sink plumbing wise. So the sink drain/vent underneath has the triple risers for the vent system. About two years ago I rebuilt the rotted drain plumbing underneath that was actually caused by a clogged vent system. After fixing the rotted black pipe drain system, I also cleared the vent system so the kitchen sink and dishwasher actualy "breathe" like they should after I bought this house back in 2002.

As part of my kitchen remodel I installed a large deep double basin apron style sink. To get that installed I removed the garbage disposal since I never liked the damn thing anyway. My ex would cram all sorts of food waste stuffs into the garbage disposal. Usually no bog deal but in my house the kitchen/diswasher drain system has a near 20' run through the floor before getting to the darin stack in the basement.

All good now, everything works, drains, etc. Except every now and then the dishawasher makes a very obvious "ggggrrrronnnn" sound like a belch when it changes cycles. The dishwasher drain used to be routed through the garbage disposal, but now it connects directly to the drain point that the garbage disposal connected to. Makes me wonder if the garbage disposal acted like a muffler or resonator that let it breathe better. Or perhaps, the dishwasher drain is not totally effective and the dishwasher belches as it tries to force the draining action.

Same problem here. I have a double basin with separate traps, so I just drop the plug in the strainer basket on that side to quiet it down. I'd love a better solution.

 

[andyvh1959]

Hmm, may have just found my answer. Looked up dishwasher drains and found this:

My rerouted drain line does arc up to the sink drain connection, so I get no drain smells issues. But it does not arc up as high and does not feature a high loop like shown and does not have an air gap device. Obviaouly the garbage disposal that was there in the past acted as the air gap vent in the system. The belches started when I took the disposal out of the drain line. I'll install an air gap device under the countertop and behind the sink basin. It won't be above the countertop like the diagrams show, but it will definitely be above the highest water possible in the dishwasher and be able to vent under the countertop. Changes coming I guess.

 

[dave*99]

Hmm, may have just found my answer. Looked up dishwasher drains and found this:

My rerouted drain line does arc up to the sink drain connection, so I get no drain smells issues. But it does not arc up as high and does not feature a high loop like shown and does not have an air gap device. Obviaouly the garbage disposal that was there in the past acted as the air gap vent in the system. The belches started when I took the disposal out of the drain line. Changes coming I guess.

I have always used version C in your diagram when installing dishwashers. Some installers leave the hose laying on the cabinet floor.
I hear the drain water flowing into the drain. It's a steady flowing sound.
But I would not call it a belch. Although I have been known to belch myself.

 

[no704]

Maybe an air admidtance valve might help??

 

[Hank11]

I have a little Studer vent in mine. The vent is up almost touching the underside of the counter top.

 

[Fav Onefour]

Try option C before adding an air gap vent.
The biggest mistake I've seen when people do option C is that the loop is often mounted too low. Try to mount the loop right up to the bottom of countertop.

 

[dave*99]

I've used the PEX supports to hold up the drain hose. Or just a cable tie.

 

[PWC Repair]

My time is better spent elsewhere than wondering about the noises my dishwasher makes .

 

[dave*99]

Some are quiet. Some are not.

 

[egdede]

Funny joke bro...

 

[Milton Shaw]

The drain hose should be as high up as the counter top or the water drain has no valve on it and can drain all the water from the dishwasher as its running. Same on washing machine drains. That loop is designed in for a reason. I have seen a washer installed on a well system that ran the well dry because it didn't have a high loop in the drain hose to prevent the syphoning of water out of the tub. I have seen dishwashers empty out during the cycle as no loop. The worst on I saw was a older man that his wife had died just before the remodeled kitchen was completed. He took over the kitchen and finally about 6 months down the road had a service call because the dishwasher was not cleaning. The garbage disposer plug had never been removed and he had been washing with the same water for 6 months.

 

[Chaznsc]

Well, you tell your wife to mind her manners!

 

[sherlocktk]

Hmm, may have just found my answer. Looked up dishwasher drains and found this:

My rerouted drain line does arc up to the sink drain connection, so I get no drain smells issues. But it does not arc up as high and does not feature a high loop like shown and does not have an air gap device. Obviaouly the garbage disposal that was there in the past acted as the air gap vent in the system. The belches started when I took the disposal out of the drain line. I'll install an air gap device under the countertop and behind the sink basin. It won't be above the countertop like the diagrams show, but it will definitely be above the highest water possible in the dishwasher and be able to vent under the countertop. Changes coming I guess.

I had the same issue 15 years ago before I knew anything. Moving to option c removed it as the drain system is essentially air free once it starts.

 

[andyvh1959]

I think what I may be hearing is the discharge pump cavitating when it starts because it is not flooded. I'll install the air gap valve and get the discharge hose rerouted as high as possible. That will keep the discharge hose filled up to the high point.

 

[BurtEggley]

make sure the washer screen or filter is not plugged with debris. We learned that our Bosch has two layers of filters and we were only watching the top one. Once we read the manual again, lifted it out and cleaned the lower screen, draining has been so much better. We later added an air trap but that was partially because we put a new sink in and it had a spare hole so why not.

 

[andyvh1959]

Good points, I'll check the filters when I pull the dishwasher out to check the drain hose routing. When I took out the garbage disposal I may have pulled out more of the drain hose not knowing why there was so much hose involved. I may have created part of the issue when I rerouted the hose.

 

[BurtEggley]

the whole idea of an air gap etc., is to keep drain water from backing up into the dishwasher where your eating dishes are.

 

[andyvh1959]

I installed an air gap valve into the dishwasher discharge hose, and located it up as high as I could under the countertop (still just a bit higher than the full sink water level). And,.....it still belches. I'll have to pull out the dishwasher from the cabinet and possibly replace/reroute the discharge hose. I suspect the dishcharge hose allows the pump to drain out and cavitate when it cycles until enough water runs through it.