Sewer Smell from Dishwasher area

[Norbert]

We have a septic tank, not municipal sewer. We have no garbage disposal. Our dishwasher is not adjacent to the sink. The drain hose goes through the floor into the basement and attaches to a PVC J-trap, which then connects via a 8" lateral to the PVC waste pipe that exits the house to the septic system. There is no loop in the flex hose, but it connects to the J-trap.

At the point where the short lateral connects to the main pipe, there is a pop-up vent above the junction. I am not sure if that is the proper name for the thing. In the first floor kitchen, around the counter area where the dishwasher is, we get a strong sewer odor, which seems to be stronger when we use water, whether it is the upstairs showers, the basement washing machine, or whatever.

Any thoughts?

[Gary Swart]

Let me start by saying, I'm not a plumber, so there may well be some plumber who respond to your question with a better answer. Your DW is not connected properly. The drain hose should loop under the counter, over the DW, through an air gap, and then into the sink drain. Now, I know your DW is not adjacent to the sink, but I believe it still should do that. I think your p-trap is siphoning dry because of lack of venting, and this is allowing sewer gas to get into the DW.

[Norbert]

The drain flex hose appears to go into the basement, where I can see it coming through the floor. Is it possible to loop the flex hose there before going to the trap?

I should probably post a picture if that would help.

I may replace the dishwasher, since it is older and may just have the installer do whatever is needed.

I don't see a way to get the drain hose to the area under the sink.

[jadnashua]

That's not a safe and effective way to connect a dishwasher. The reason to run the hose high up to the counter is so that it will not siphon all of the water out, and help to protect the thing from sewage from backing up into the DW if there was a clog somewhere. An air gap will work more reliably, and is required in more and more places. By running it down to the drain, you've made a direct connection to the sewer (which isn't allowed) and have no means to prevent sewer gasses from coming back into the DW, which isn't a particularly healthy thing either.

You need to find another way to get this into the drain. You may have to get creative. You won't get an install for a new one that will pass code without spending some bucks.

Hopefully, somebody will have some ideas on how to fix this. It would help if you posted a picture of what you have now and maybe a layout of where the DW is in relation to the sink. Does the DW back up onto another room with a drain (say a bathroom), where you migth go through the wall into the vanity?

[master plumber mark]

Usually a dishwasher has to have a loop in the line
higher than the water level or the water will jsut
flow out into the drain...

it is supposed to be pumped out after the cycle is completed.........


We have used miles of Radiator hose in the past years
to run dishwasher lines from island sinks over and up to the arm in the disposal .....

I dont remember the actual size to use.... I know that 1/2 pipe fits tight inside the radiator hose and you put a SS clamp on it and it works great.....


Perhaps you ought ot pour some bakeing soda or some bleach into the dishwasher and see if that solves the smell problem

before you go nuts trying to re-do the whole line....

[fidodie]

My previous dishwasher was set up the same way, but...

To meet the air-gap code...
some model dishwashers have a built in air gap that is "closed" with the delivery of the dishwasher, It is exactly for this reason - just open it and you provide the necessary gap - only problem is it is usually on the back. check your manual. (they built the loop into the system, no need to worry about water getting past the drain w/o being pumped then, although in a recycling system, i would imagine that there has to be valving to close the drain)

perhaps your install is pre-dates the code - mine was 1962...

i suspect that the pop-up vent you are speaking of is a redi-vent or sure-vent (see picture). more specifically an air admitance valve. they have a limited life, and can be replaced if the sewer gas is escaping out of this valve - they are not expensive - about $6 for 1.5"
if it just started to smell after a long time of not smelling, this is the more likely source.

As mentioned - any possibility of effluent getting into the dw is dangerous, since i may be offering a solution that doesn't meet current code.