tinmanwpk
Well-known member
Quick one - Should a drain line for a washing machine in a new house have a trap or just drain straight to the main drain?
Quick Plumbing Question
- Thread starter tinmanwpk
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Meursault74
Well-known member
should have a trap, unless you enjoy the smell of sewer gas.
https://www.thespruce.com/the-purpose-of-a-drain-trap-2718770
"Large plumbing fixtures such as showers, tubs, and washing machine drains also have drain traps, but they are not as easy to see because they are under floor level or behind walls. Tubs and showers have traps that are harder to get to and either require crawling under the house or cutting a hole behind the tub or shower and digging out the area where the trap is located. Washing machine drain traps are mostly in the wall, and to access them you usually have to cut into the wall as well. "
https://www.thespruce.com/the-purpose-of-a-drain-trap-2718770
"Large plumbing fixtures such as showers, tubs, and washing machine drains also have drain traps, but they are not as easy to see because they are under floor level or behind walls. Tubs and showers have traps that are harder to get to and either require crawling under the house or cutting a hole behind the tub or shower and digging out the area where the trap is located. Washing machine drain traps are mostly in the wall, and to access them you usually have to cut into the wall as well. "
Gunfixr
Well-known member
Yes, unless you don't mind the stink of sewer...............
nadogail
Well-known member
The stink of sewer is unappetizing and your cook will not feel like feeding you well.
TLCObsession
Well-known member
Trap is frequently down at the floor level depending on how it ties in and how it is vented. When I rough in it is almost always down at the floor.
dave_dj1
Well-known member
Trap just below the box.
rlitman
Well-known member
Exactly. It cannot be right below the box, because it needs a little stack to guarantee it will not overflow.
When I did this recently, I put a service panel in the wall, and used a trap with a drain plug. I doubt I'll ever have to open it, but it seemed like a good idea.
rburke65
Well-known member
A trap. I figured ou5 this my hard knocks
K'ledgeBldr
Well-known member
Well...
If you consider 18”-30” “just below the box”, OK.
https://plumbingcodestuff.tumblr.com/post/147932728093/randomsudoisms-diagram-of-standpipe-for-a/amp
...most be a “horseshoe and hand grenades” thing???
TTTTTT
Well-known member
Often if you have laundry tub beside, its tied into that line just before the trap. A stand pipe beside the tub just above tub height so the discharge pipe can go right in.
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CJ7VFR
Well-known member
What do you do in homes that have a septic system, and the washing machine is in the basement, and the discharge pipe for the washer is coming out of the wall at 48 inches (4 feet) up off the floor?
Jim
rlitman
Well-known member
You make sure that your washer's pump is rated to lift water high enough. Some will be, and some will not.
Pntyrmvr
Well-known member
I put my laundry tub drain into a box with a float and a pump in it. From there up and into the septic.
For the life of me I can't remember it's proper name. Anyway, fully automatic.
For the life of me I can't remember it's proper name. Anyway, fully automatic.
I appreciate the responses. My home was built a little over five years ago by a national builder and it has a laundry room that smells like sewer gas. I know a trap should have been installed but since it smells badly I wonder if one was installed. Now there is only one way to find out, and that is to demo part of my wall. I guess I will have to do it to find out. At least the other side of the wall is in the garage so I can put a metal panel to cover up the mess. Oh, well, nothing ventured nothing gained.
Thanks to all who helped.
Thanks to all who helped.
rlitman
Well-known member
Ugh, that *****. Could it be something rotting in the trap? I'd send a camera down the drain before demolition.
Don't go opening up ways for air to get between the garage and the house. That's a fire code no-no and a CO poisoning risk.
Meursault74
Well-known member
Maybe the water in the trap (if there is one) is getting getting pushed or siphoned away. Maybe try pouring in some water in the drain after the washing machine has finished and see (or smell) what happens.
duneslider
Well-known member
Do you have a floor drain in this laundry room? Floor drains are notorious for drying up and letting sewer gas through. They need to have water added periodically to keep the trap full.
rlitman
Well-known member
Or have a trap primer, or a waterless trap seal insert.
CJ7VFR
Well-known member
Yeah, I got that covered. My washing machine manual says it can pump water up to a max height of 65 inches above where the drain pipe comes out of the back of the washing machine.
Because of distance my discharge pipe is located off the floor, and the fact that my washing machine has the max pumping height of 65 inches, I could only get a 16 inch standpipe on top of the trap.
In order to compensate for a shorter standpipe, I upped the diameter of the standpipe from 2 inches to 3 inches. So my 16 inch standpipe has the same volume as a 36 inch standpipe that is 2 inches in diameter.
I was just curious if this would pass code or not since the actual volume of water that my standpipe can hold is more than a code compliant 2 inch diameter standpipe that is over twice as tall.
Below is my setup for reference.
Jim
Attachments
TLCObsession
Well-known member
You could try snaking the drain. With a lightweight snake like the cheap HF drum style, I can sometimes feel and other times hear where the snake is going. Bonus if you pull a bunch of lint or dog hair that was in there creating a smell.
You may also have something super dumb: the trap may be there, but the vent might not be connected - The way people (especially production builders!) build, nothing surprises me anymore. I have seen all kinds of ridiculous stuff.
Off topic but same idea: Friday nighty I installed a new hot tub at my partners house. I pulled an access panel off to get a better shot at drilling for the flex conduit. There was a manifold for the jets distribution. All of the crimp rings on the outside of the manifold (think a narrow V engine with one cylinder bank along the outside) were crimped - all the ones along the inside were on the tubing, but never crimped... half of the LED lights were just zip tied in bundles and not inserted into their bezels. All of the boxes on the QC inspection sheet were signed off....
You may also have something super dumb: the trap may be there, but the vent might not be connected - The way people (especially production builders!) build, nothing surprises me anymore. I have seen all kinds of ridiculous stuff.
Off topic but same idea: Friday nighty I installed a new hot tub at my partners house. I pulled an access panel off to get a better shot at drilling for the flex conduit. There was a manifold for the jets distribution. All of the crimp rings on the outside of the manifold (think a narrow V engine with one cylinder bank along the outside) were crimped - all the ones along the inside were on the tubing, but never crimped... half of the LED lights were just zip tied in bundles and not inserted into their bezels. All of the boxes on the QC inspection sheet were signed off....
rlitman
Well-known member
That looks like an S trap to me. Aside from S traps being bad, if you did a P trap it would be a few inches lower.
LS6 Tommy
Well-known member
I may be wrong, so someone please correct me if I am, but I'm pretty sure your S trap is not code compliant.
EDIT- Rlitman beat me to it...
Tommy
like2wheel
Well-known member
If it's a front load washer, that might be your problem. Search that, you'll find plenty of issues with smells from them.
nadogail
Well-known member
IMHO, that 65" figure is about 5' above the level of the outlet of the pump; gravity should take care of the rest of the draining.
rlitman
Well-known member
Good point. I leave my washer door open when not in use. Front loaders will get a moldy smell after just a few days sealed up.
b-boy
Well-known member
Yep. They stink bad. I've tried everything out there to fix the problem, but nothing works.
Whenever the machine is used after a few days of sitting, the first load of drain water smells like the sewer backed up.
rlitman
Well-known member
They harbor mold in a number of closed spaces that need cleaning and ventilation.
First, take out the soap drawer. Usually there's a place you can press to release it for removal. Wash its underside, and then look into the cavity with a flashlight. It'll be nasty in there. I use a spray bottle of mold removal products. Got Tilex or something like that, preferably with a foaming spray nozzle? Spray all over in there. Focus on the top. The bottom drains into the tub. Let the chemicals sit for a few hours, and spray it again. When the bulk of it has dripped off, put the drawer back in.
Next, run an empty load with bleach and dishwashing detergent (put these in the soap location) at the hottest setting you have, and run an extra warm rinse. That usually solves mold around the drum, and running a cycle will wash out the drawer slot.
Repeat this as needed (1-2 times per year).
And remember to leave the door and soap drawer left open when not in use.