Sewer Smell in Laundry Room
We are getting a sewer gas smell when we do laundry! This started as just the odd time and then became almost every time we did laundry. We have a brand New Kenmore front load washer and front load dryer(both electric as we have no natural gas in our house) - but the smell had happened before these new appliances but only once or twice a year. It seems that after the second wash load the smell starts. It is terrible! We checked all drains and all have the P-trap. We tried pouring every type of "drain" chemical there is down every drain and nothing helped. The smell would start in the laundry room and make its way up to our bedroom bathroom! The odd time our main bathroom (upstairs as well) would have a mild sewer smell coming from the drain as well. So we called in a plumber about 2 months ago. He checked all drains and they were fine. He put a snake down the sewer vent on the roof and said he really couldn't find any problems. The smell was gone! We were so happy. Well today the smell is back! I did one load of laundry in the wash and it was fine. BUT... as soon as I put the load in the dryer the smell came! (no 2nd load of laundry washed either) Could it be from something else other than the plumbing? Our dryer exaust vent goes from the back of our dryer straight outside (only 18inches). No idea why the smell is back or what caused it. However... I did notice a very slight sewer smell in the main bathroom sink drain again the past couple days but poured "drano" down it and it went away. The smell seems to be coming from in the ceiling! We had plumbing work done in our master bathroom above it in the spring. We put in a new tub and found out the old one had leaked. The drywall had black mold on it and was shot so it was all cut out there... so we can really smell it as the ceiling is wide open. Could there still be mold in the ceiling causing this smell and how would this be related to running our washer or dryer? AAHHH... what could be causing this.. I don't even know what professional to call for help!