Dishwasher/Plumbing Question

[Byron Trantham]

My dishwasher and everyone I've seen installed, has a "vent" on the counter that connects the dishwasher drain and garbage disposal. I have just finished with a client who had a new DW installed along with granite counter tops and the "granite guy" said the "vent" isn't necessary, just connect the DW drain to the GD. If that's correct, what is the thing on the counter for? Are there codes issues here? It would be nice not to have to clean the bugger out every once in a while.

[Jim Becker]

'Depends on your plumbing. The sink should have a vent stack already and if so, you don't need the one-way counter-top vent.

[Bill Webber]

The counter top thingy is an air gap. It keeps the dishwasher from being able to back-siphon into the water supply lines feeding the dishwasher. Current thinking is that an attachment above the trap in the sink accomplishes the same thing. I don't know how it attaches to the GD but I suspect there is a place for it.

[Al Willits]

Find the model of the unit in question and look at the installtion manual that came with it.
Most units need an anti siphoning loop and the manual should tell you what else is needed.

Al

[Jim Becker]

My Fisher-Paykel dishdrawers didn't require any extra venting nor was there provision for one. The old hotpoint that came out didn't have one, either.

[JayStPeter]

Those air gaps are pretty old school. You need to check you local code, but I can tell you that they were removed from code in Falls Church by the early 90s. I've replaced 2 dishwashers since and removed the air gaps from the system in both houses. My new house never had one. I think the fact that newer garbage disposals support the connection eliminates the old problems. In both cases, I had far less problems after eliminating the devices. If you're on septic w/o a disposal, I don't know the answer :cool:

[Jim Becker]

Jay...septic without a disposal here. (We compost anyway) No air gap.

[Al Willits]

Little confused here, but if by air gap you mean the anti siphon feature, this loop normally has to be there in almost all the DW I know of, will they work without it? ya maybe, but the installation manuals I've dealt with advise to have it, and many are now coming with that loop permanently a fixture of the DW
There is also a vent on the inlet side of some DW's and that needs to be there also.

Probably missing something here, as usual... :)

Al

[Ken Garlock]

I have had 4 or 5 DWs installed over the past 30 years. NONE of them had a separate vent. All of them had, and my surrent one has, the DW drain hose looped up to and attached to the top of the interior of the cabinet. It then decends to the garbage disposal. The garbage disposal will form the vacuum break that these vents are supposed to provide. IMO, if you attach the drain hose on the sink side of the sink trap, you are in good shape.

These vents sound like some OSHA guy working over time.:rolleyes:

[Jeffrey Makiel]

Ken...I don't think OSHA has anything to do with this. It's more driven by local code. Also, OSHA doesn't apply to private citizens within their residential dwellings.

What always cracks me up is that some towns say 'yes' and some towns say 'not necessary' to many things such as an air gap for a dishwasher. The last I checked, poo poo flows downhill in all towns the same way.

-Jeff :)

[Robert Mickley]

Thats funny, the only air gap my dishwasher has,,,,is around her lips when she starts talking :D

[Byron Trantham]

JayStPeters is correct. I contacted a local plumber and he confirmed that the air gap is no long code. You can connect the drain hose of the DW directly to the garbage disposal. This is really nice information. That eliminates two connections UNDERNEATH the sink!:D

Thanks for all your input.

[Jeffrey Makiel]

Oh. By the way. Garbage disposers are not allowed by code in my town! :)
-Jeff

[Al Willits]

""""""""
All of them had, and my surrent one has, the DW drain hose looped up to and attached to the top of the interior of the cabinet.
"""""""
That would be the ainti siphon feature and what I was refering to, by vent do you mean like your sink drain is suppose to have?
Ifso, leastwise here in Minn, its not needed.

Some also have a vent on the inlet side, this is a internal vent and you wouldn't have to deal with it, but I don't think its what you mean, but dishwashers can have several types of vents.

Al

[Ken Garlock]

Ken...I don't think OSHA has anything to do with this. It's more driven by local code. Also, OSHA doesn't apply to private citizens within their residential dwellings.

-Jeff :)

Jeffrey, I knew that when I wrote the comment. I just like to bad-mouth OSHA any chance it get.:D I should have made my comment more obvious.:o

[Ken Garlock]

Thats funny, the only air gap my dishwasher has,,,,is around her lips when she starts talking :D

LOFL. Robert post a picture when your 'dishwasher' gets done cleaning your 'clock.':D