Dishwasher

[joe]

Can I install a dishwasher in a kitchen where I do NOT have a garbage disposal, to connect the waste hose ??

Is a disposal "required" for pproper dishwaher performance?

[Wayne Boatwright]

On Sun 09 Jul 2017 11:56:01a, told us...

No, you do not need to install a disposal when you have a dishwasher. If you have a double sink, one of the drain pipes has to have a side inlet for the dishwsher drain hose to connect to. If you only have a single sink, then that same type of drain pipe would be used so that you can connect the dishwaser drain hose.

In one of our earlier homes we had no disposal and the drain hose from the dishwasher was connected directly the side of the sink drain pipe.

[Ed Pawlowski]

Disposal not required. You have to replace a section of the drain pipe with one that has a tee to accept the drain hose from the dishwasher. Any handyman can do it if you cannot. Your appliance dealer may be able to have his installer do it too.

[Terry Coombs]

Yup , you can buy the adapter tailpiece (plumber talk) at most well-stocked hardware stores . Got one in my kitchen right now , out here in the woods that organic waste goes to the critters - wild or domesticated instead of into a disposal .

--

Snag

[Stormin' Norman]

No, and IMHO you are better off without a disposal, I think they are a huge pain in the ass and have little value.

You will simply install a new sink drain tail piece, with an additional inlet for the hose coming from the dishwasher air gap / drain.

I am not sure if plumbing code in all states require an air gap as part of the dishwasher installation. For more information, see:

[Wayne Boatwright]

On Sun 09 Jul 2017 01:14:31p, Stormin' Norman told us...

Air gaps are not required in AZ unless in certain commercial buildings and high rise apartment buildings.

[Stormin' Norman]

That is interesting Wayne, thanks. If it were me and if I had an extra punch-out in the sink, I think I would install one regardless.

[Wayne Boatwright]

On Sun 09 Jul 2017 02:49:36p, Stormin' Norman told us...

You're welcome. With the exception of one apartment, I've never lived in any residence where a sink had an air gap, and that includes having lived in 5 different states. I don't know what the codes were in any of those places, but air gaps were few and far between.

[Ed Pawlowski]

I wouldn't, just a loop. Had dishwashers for 50 years and no problems without it. Anyone know of a problem actually caused by a DW that back siphoned into the water system? Yes, it can get into the DW, but the purpose of the air gap is to protect the domestic water supply.

[Stormin' Norman]

The air gap with a dishwasher prevents drain water from backing up into the dishwasher and contaminating the dishes. Doesn't happen very often, but if it does happen it can make people quite ill.

Not sure how a dishwasher air gap would protect the potable water supply, but maybe.

[Dean Hoffman]

I guess it's possible if the water supply pressure failed at the same time.

[Wayne Boatwright]

On Sun 09 Jul 2017 05:32:51p, Ed Pawlowski told us...

Never had a problem with a loop, and only lived in one place that had an air gap.

[Ed Pawlowski]

That is the purpose of it. Id pressure drops while the machine has water in it, there is the possibility water can siphon back to the water supply. Same reason backflow preventers are required for sprinkler systems and some towns want them on every residence. Overkill, IMO. I can see it in industrial settings. Our boiler feedwater systems have to have them but we're talking 125 psi pressure if the power went out to the city system.

[micky]

I don't keep track of other people's problems, but I had a chicken bone, the one next to the drumstick, stick in my airgap and iirc it kept the DW from draining. I thought it was the pump, or the hose was clogged, and it took a while to find the thin little bone.

[gfretwell]

Not likely with the design of those diaphragm valves, even if the water supply was in the bottom of the dishwasher. The water pressure is what opens the valve. No pressure and the valve slams shut. In real life the sump of the dishwasher is air gapped from the supply line.

[Stormin' Norman]

That was my understanding. Maybe Ed can explain the logic behind his reasoning.

[Ed Pawlowski]

Not my reasoing. It is code in some places and their reasoning is if the water system loses pressure the water in a running DW will not siphon back into the water lines. Nor will it suck water from your drain lines. It is the government saving us from ourselves.

I think it is way overkill and not needed.

[trader_4]

I agree it's overkill, it's not required here in homes in NJ either. If you look at the dishwasher install instructions, they say a high loop is sufficient unless code requires an air gap. The high loop works for me. It's almost as much protection as an air gap, without extra, useless holes in the sink and more work installing.

However, I think Stormin is right, the purpose is to prevent waste water from going into the dishwasher, where there may be dishes that were already cleaned, not to keep waste water out of the fresh water system. I can see how the former can happen, but not the latter.

[trader_4]

But then dirty dishwasher water complete with detergent can get back into the fresh water supply that way anytime. It seems if that's the concern, then an additional check-valve or similar in the DW is the solution. Which is an interesting question, I would think they probably do have something in there to prevent that, but IDK.

[trader_4]

Did you call 911? Have someone perform the heimlich maneuver?

and iirc it kept the