Why is the smell of sewer coming from the washing machine drain

Hey mohave:

A sewer smell from the washing machine drain could be that the trap is getting siphoning due to lint in the ptrap. Here, lint in trap can act to virtually suck the ptrap dry of water by acting as a WICK...so that could cause this.

Otherwise, drain or vent may be clogging and causing back pressure and bubbles (which would release sewer gasses)...

Either way..seems you have an issue with the drain/vent and will need to clear the issue.

Start by flushing toilets, draining sinks and while they drain see if you hear anything going on at the washing machine stand pipe (pipe coming out of trap)...if you hear gurgling/bubbling, then will need to rent a sewer snake and snake the drain line.

NOTE HERE..that this could be issue at washing machine...could also be issue with the MAIN DRAIN TO YOUR WHOLE HOUSE. I assume this washing machine is lowest fixture in the house...yes..?

Run water to fixtures (basically, try to flood the drain system (watch for too much water to overflow))...get back to us with more information...Thanks...Mark

Can you describe how your machine is drained, is there a black pipe coming from the machine to a wash tub or does it go to a stand pipe or what? Thanks