Bad smell from Washing machine or Drain...

My wife and I notice a bad smell from either our washing machine or the washing machine drain ever once in a while.  It was BAD on Sunday when we got home after being away since last Tuesday.

This may have been going on for awhile.  We had a cat that was marking his territory in different spots of the house and I NOW think that some of the smells we had were due to this drain or machine issue.

I installed the washing machine and the plumbing.  I used on of those boxes that has the 2 water lines and a drain line.  The standpipe is about 45 inches long (the trap is below the floor level - accessible from the basement).  It has a "P" trap and then about 4' of near horizontal run.  I say near horizontal but it is sloped slightly greater than 1/4" per foot.  The drain then connects to the main stack. 

There is no vent line for any of the house.  The house is old.  I am not running a new vent line (if you saw the way the house was constructed and how it would need to go through the house you would understand).

My first thought is that the machine itself is stinky.  I will try to wash it out with baking soda and bleach (internet recomendation). 

If not a stinky machine, is there a way to improve the drain?

Thanks!

Rob R.

Is it a front loading machine?

If so, leave the door open or it will grow mold and stink.

If not, then yeah you've got standing water/mold somewhere in the drain, which isn't draining.

Using the washing machine more often keeps this at bay by forcing the water to move.

Also leave the soap drawer open while not in use. 

For front loading smell, my mom has had great success with this product: http://www.technofresh.net

She had to follow a pretty specific set of instructions to get it done; we're trying it next weekend with ours.

You have one of these boxes?

My old 1894 house is about the same, wouldn't drain, stunk, got one of these siphon vents.  Draining picked up and no backwash from the sewer system.

I would run a light load of say shop rags with bleach involved, get a siphon vent and see if that helps.

914Driver said:

You have one of these boxes?

 

My old 1894 house is about the same, wouldn't drain, stunk, got one of these siphon vents.  Draining picked up and no backwash from the sewer system.

I would run a light load of say shop rags with bleach involved, get a siphon vent and see if that helps.

Yes, I have one of those boxes.

Older top load washing machine. 

Do I just put the AAV about a foot after the "P" trap?

I have the same issue, my dishwasher and kitchen sink are on a non-vented drain and whenever I run the dishwasher or run a lot of water through the sink it stinks bad. I'll have to try the AAV valve on that drain (along with fixing some of the shoddy plumbing on that drain line).

Any chance something crawled under the machine and died? 

In reply to slantvaliant :

Not really.  It isnt that bad.

Its liek if you go into somebodies house that has lots of pets and lots of carpet...  You smell it, but it isnt horrible....

It wasn't me, I swear!

If it only happens after not running water down the drain a while, maybe all the water in your P trap is evaporating, so the sewer gas can come right back up the line.  Poor venting can also create a syphon effect that will pull most of the water out of the P.

Streetwiseguy said:

If it only happens after not running water down the drain a while, maybe all the water in your P trap is evaporating, so the sewer gas can come right back up the line.  Poor venting can also create a syphon effect that will pull most of the water out of the P.

This is what I was thinking.  Without vents, using other drains (especially toilets) can suck the water out of the traps leaving an open path for gasses to come back.  I had this problem in my old house.  The basement bathroom wasn't vented, so every time I flushed I could hear the sink drain bubbling and then it would smell bad.  One of those Oatey vents cured it.

I have also had just washing machines get smelly.  They always leave a pint or two of water in the bottom.  The vane pump will lift the water up to the drain, but once it catches air it just lets the water between the pump and the drain gravity feed back to the bottom.  A good heavy bleach load usually cures it for a while, but it always comes back.

Once a month whether it needs it or not.

Your plumbing system DOES vent.  If not through a vent pipe, then somewhere else.

You are probably siphoning the trap dry, and the sewer is then venting into your house through the washing machine box.

Vents are important.  Use the AAV if you have to.

I had this issue and it was the machine. Stuff hets trapped between the drum and the tub and stinks. Took the machine apart cleaned it out and no more stink. It can get really nasty especially if you let it sit for a while with the top closed.  Less stink if you use the machine regularly and leave the top open between washes. 

Definately try running a few cleaning cycles through the machine.

Last time I pulled the drum out of my washing machine, I was stunned at the amount of disgusting sludge that had accumulated on the outside of the drum and the inside of the tub. Any wonder it started to get a bit of a funky smell now and then.

It's amazing how much dirt, oils, grease, skin cells, laundry lint and God only knows what other crap accumulates in something that's supposed to clean things and constantly has detergent in it.

 If you haven't actually said what it smells like. Does it smell like sewage? Does it smell like dead animals? Does it smell like mildew? 

These are clues...

In reply to wvumtnbkr : 

right in the soap isle where you buy your tide etc is a product for the smell 

put it in once a month and run it 

Pore some vinegar and baking soda in there and run a cycle. 

Standpipes are suppose to be a max of 24" to the p trap, then vented at least 2 pipe diameters away from the weir of the trap, but no more than 2 times the diameter of the pipe plus two....  but in feet instead of inches.  1.5" drain needs to vent within 5 ', 2" within 6', 3" within 8', etc.  If the standpipe is too long, you have a 1.5" drain, and its not vented, you can create a siphon when the washing machine discharges.  Especially true with a new washing machine with a strong pump, and an old slightly clogged drain.  This will cause the water in the trap to siphon out leaving an air space for the sewer gasses to enter the building.  Try bleaching the standpipe first.  If the smell continues, pour a cup of water in the drain after each use to make sure trap water seal is restored.  If that solves the problem come up with a seal where the washing machine discharge hose slips into the standpipe to prevent sewer gasses from passing thru.  I literally just had Mazda605 come over and help me carry my new front loader up the stairs.  Oh the joy of what awaits me once I go pick up new hoses.  Looks like I caught the old ones just in time.

Ya speaking of hoses I need to change mine they are 8 plus years old now.  Just noticed this the other day when I tried turning off the valve they attach to and found it has corroded and is now stuck open.  I have some plumbing in my very near future. 

We have a top load and try to do the following:

 - Run our bleach load last. That way, there's going to be some bleach residue in the washer

 - Keep the lid open when not running

Both help. 

I agree that it sounds like your P trap is not working as designed (either evaporation, suction, etc. causing it to stop blocking sewer gas.)