smell from washing machine drain

scottcc · Jul 24, 2014

Normally I wouldn't hesitate to call in a plumber for this, but with a new baby only days away from being born and my wife on maternity leave I'm trying to save some pennies and fix this problem myself (or at least try the obvious things first).

I've got a sewer smell coming from the washing machine drain. The smell seems to be strongest just after the machine has been used. The washing machine itself is new (about 2 months old) and is used regularly (2-3 times per week). The drainage hose is correctly elevated and installed. I've removed the P-trap and cleaned it out. Sure enough, the trap was a bit filthy...it now sparkles on the inside. Unfortunately that hasn't solved the problem and the smell is still there. I don't know if it makes a difference but the house is on 3 levels with the washing machine on the middle level.

Any suggestions for what to check next would be much appreciated...

Whyme · Jul 24, 2014

Whats the washer drain connected too, sounds like the water seals being pulled or siphoned for some reason.

village idiot · Jul 24, 2014

fit an anti vac trap to it

scottcc · Jul 25, 2014

Whyme said:
Whats the washer drain connected too, sounds like the water seals being pulled or siphoned for some reason.

Thanks for your reply. The washer drain is connected to a stand pipe (the drain house is about 5 inches down into the pipe) into a P-trap. It's separate from the kitchen sink/dish washer drain. I'm not 100% sure, but I don't think siphoning is the issue. The trap always seems to have water in there. Maybe replacing the seals is worth a go? They don't leak water, but perhaps sewer gas?

Whyme · Jul 25, 2014

Sewer smells dont usually get back thats the idea of the trap water seal. sometimes if theres a partial blockage in the pipe the water going down can make air in the pipe bubble up into the trap causing smells..try looking further down the pipe.

scottcc · Jul 26, 2014

Whyme said:
Sewer smells dont usually get back thats the idea of the trap water seal. sometimes if theres a partial blockage in the pipe the water going down can make air in the pipe bubble up into the trap causing smells..try looking further down the pipe.

Thanks for the tip. I've got a friend coming over tomorrow and we'll get the washing machine out and start working downwards (the horizontal waste pipe from the trap seems clear). Just out of interest here are two photos of the trap; if you compare the two photos you can see that the entire waste pipe can be pulled forward about 2.5 inches - does that seem like a normal amount of play?

https://www.dropbox.com/s/2zkowsaofy8ve2z/trap1.jpeg

https://www.dropbox.com/s/daa9yvhcw3ttgem/trap2.jpeg