Thread: Dishwasher Drain

At an inspection today the dishwasher drain was discharging into a standpipe under the kitchen sink. It had a trap and the air break that is required so I didn't see a problem with it as far as the code goes. Does anyone know why this would be a problem.

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Originally Posted by James Duffin

At an inspection today the dishwasher drain was discharging into a standpipe under the kitchen sink. It had a trap and the air break that is required so I didn't see a problem with it as far as the code goes. Does anyone know why this would be a problem.

I have never seen one connected like that. A question I would have is; How is that drain line connected to the standpipe? If it is just hanging on the edge of the pipe I could see this as a problem.

I looked at an install guide for a Whirlpool DW and it only list two methods for attaching the drain.
1. Attach to the food disposal if it has a place for it.
2. Attach to the drain line above the trap.

The disposal method is recommend due to food scraps that might be discharged.

Originally Posted by Scott Patterson

I have never seen one connected like that. A question I would have is; How is that drain line connected to the standpipe? If it is just hanging on the edge of the pipe I could see this as a problem.

I looked at an install guide for a Whirlpool DW and it only list two methods for attaching the drain.
1. Attach to the food disposal if it has a place for it.
2. Attach to the drain line above the trap.

The disposal method is recommend due to food scraps that might be discharged.

I have never seen connected like this either but when I read the code requirements it sounded like it was okay. There is no way it can come out of the standpipe since it is so close to the countertop. Here is the code section about this:


802.1.6 Domestic dishwashing machines.

Domestic

dishwashing machines shall discharge indirectly through an
air gap or air break into a standpipe or waste receptor in
accordance with Section 802.2, or discharge into a
wye-branch fitting on the tailpiece of the kitchen sink or the
dishwasher connection of a food waste grinder. The waste
line of a domestic dishwashing machine discharging into a
kitchen sink tailpiece or food waste grinder shall connect to
a deck-mounted air gap or the waste line shall rise and be

securely fastened to the underside ofthe sink rim or counter.

I don't see a problem with it.

Thanks guys....just sent it on as no problem.

indirectly through an air gap or air break.


Recheck the definition of an air gap and an air break.

The soft copper looks pinched/flattened somewhat at the inside of the first bend, looks like an elbow fitting at its termination sitting IN the ABS stand pipe.

Contact between the inside or top edge of the drain stack pipe to the copper wouldn't be an "air break" or "air gap", any portion of the copper which was within, and below the flood rim of the stack pipe wouldn't be "indirect".

The flood rim of the stack pipe is right up to the underside of the counter, and too high for the high loop, back spillage and contamination is possible (perhaps you are unfamiliar with bioslime in plastic drains?).

Originally Posted by H.G. Watson, Sr.

indirectly through an air gap or air break.


Recheck the definition of an air gap and an air break.

The soft copper looks pinched/flattened somewhat at the inside of the first bend, looks like an elbow fitting at its termination sitting IN the ABS stand pipe.

Contact between the inside or top edge of the drain stack pipe to the copper wouldn't be an "air break" or "air gap", any portion of the copper which was within, and below the flood rim of the stack pipe wouldn't be "indirect".

The flood rim of the stack pipe is right up to the underside of the counter, and too high for the high loop, back spillage and contamination is possible (perhaps you are unfamiliar with bioslime in plastic drains?).

This is the proper answer. Very good Snowbird .

Originally Posted by Rodger McBride

This is the proper answer. Very good Snowbird .

I got to read crazies reply in your quote. Here is the definition of a air break for you two. This is not a air gap.

AIR BREAK (Drainage System).

A piping arrangement in
which a drain from a fixture, appliance or device discharges
indirectly into another fixture, receptacle or interceptor at a

point below the flood level rim and above the trap seal.

Originally Posted by James Duffin

Does anyone know why this would be a problem.

Not me. It isn't much different than a washing machine's discharge.