Dishwasher Installation Problems

[bill smith]

I recently purchased a new dishwasher and the delivery/install people would not install it. On the unit I'm replacing, the water feed and the water drain are not hooked into the kitchen sink. There is a separate water line coming up from the crawl space into the current dishwasher. Also, the drain runs from the current dishwasher directly into the outflow from the house. See the pic below

I can install my new unit in the same fashion. My question is: Why is this considered unacceptable? And what are the ramifications of installing my new unit in the same fashion as the old?

Thanks for any help or advice on this.

 

[Terry]

I don't know of any "dishwasher" installers that will do any install that isn't cutterboard stuff.
Going into a crawl space for the connections is never done. Typically the shutoff for the water is readily accessible. The DW drain is either looped as high as possible before connectiong to a p-trap or disposer, or the hose goes to an air-gap above the counter before connecting.

 

[Sponsor]

 

[bill smith]

I don't know of any "dishwasher" installers that will do any install that isn't cutterboard stuff.
Going into a crawl space for the connections is never done. Typically the shutoff for the water is readily accessible. The DW drain is either looped as high as possible before connectiong to a p-trap or disposer, or the hose goes to an air-gap above the counter before connecting.

 

[bill smith]

Thanks Terry. Let's assume I install my new DW in the same fashion as my old one. Am I going to create any problems? I've never had any backup or odor problems in the past.

 

[Terry]

I have no idea what that is draining into so I can't really say.

 

[bill smith]

I have no idea what that is draining into so I can't really say.

It's draining into the outflow from the sink. It's just past the P-trap.

 

[FullySprinklered]

It's ugly as s*** on a dirt road, but it'll probably work.

 

[Standardairconditioner]

Let's assume I install my new DW in the same fashion as my old one.

Dishwashers are not much different than a clothes washer.

They like the fact that the supply and drain can be a few feet away from the unit.

Consider a washing machine with supply and drain directly under it, which would be not so straightforward to set up.

You would have to raise the washing machine, space for the rubber supply hoses and the machine's loose drain hose, and pray it stays this way no matter how many unbalanced loads it gets.

Honestly, the dishwasher isn't going to care where it is getting water from, and certainly not care where it is dumping the water to.

 

[Terry]

I've seen some dishwashers that start to fill with water from the kitchen sink. It was pretty murky water inbetween dish loads until I installed an air-gap on the drain side.

 

[Dj2]

I don't trust any dishwasher drain set up, except the set up in Terry's diagram.
The water supply - it can come from the crawl space. Having a shut off near the DW is a big plus.

 

[Widgit Maker]

Ifn't it wus me. I'd cut that supply line and install a Sharkbite 1/4 turn stop valve. Then connect the dishwasher with a braided supply line. I'd do that only for convenience should you ever have to pull the dishwasher out for some reason.

Why is this considered unacceptable?

The drain is line is unconventional but the only thing unacceptable is the fact that it probably doesn't go through a trap. But then it is unlikely that you would ever get sewer gases back up through the pump.
I say, if it works leave it alone.

 

[Terry]

Ifn't it wus me. I'd cut that supply line and install a Sharkbite 1/4 turn stop valve. Then connect the dishwasher with a braided supply line. I'd do that only for convenience should you ever have to pull the dishwasher out for some reason.


The drain is line is unconventional but the only thing unacceptable is the fact that it probably doesn't go through a trap. But then it is unlikely that you would ever get sewer gases back up through the pump.
I say, if it works leave it alone.

And the leave it alone method would not pass any plumbing inspection anywhere. The installers were right to not install it.

 

[Widgit Maker]

Don't disagree but who is going to call for an inspection.

 

[Cool Blue Harley]

The approved dishwasher air gap fitting is a specially designed waste back flow prevention device. When installed in the approved manner in the waste discharge piping of a domestic dishwashing machine and placed above the overflow rim of the adjacent fixture, usually a kitchen sink, it prevents contamination of the washing and storage compartment from waste and sewage backup.

It also prevents the dishwashing machine from pressurizing the disposal or tailpiece, or in this case an unknown waste line that is receiving the discharge from the appliance.

 

[WJcandee]

The approved dishwasher air gap fitting is a specially designed waste back flow prevention device. When installed in the approved manner in the waste discharge piping of a domestic dishwashing machine and placed above the overflow rim of the adjacent fixture, usually a kitchen sink, it prevents contamination of the washing and storage compartment from waste and sewage backup.

It also prevents the dishwashing machine from pressurizing the disposal or tailpiece, or in this case an unknown waste line that is receiving the discharge from the appliance.

Wow! Nicely-said! Welcome!

 

[bill smith]

I did the installation today and I think everything is ok. There is a a separate water cut-off as well as a trap in the crawlspace. All the same elements that should be under the sink are in the crawlspace. Redundant I know. The waste water pipe the DW is draining into is not unknown. It's the waste water pipe for the kitchen sink. It's just tying into it in the crawlspace rather then under the sink. The design of the drain tube provides an air gap as well. It runs up the side of the DW before it turns down and goes thru the floor. There is no disposal so no worries there. Thank you all very much for your help and opinions.