Asked on Jan 25, 2013

Sewer smell in very cold weather

Donna R
by Donna R
Does anyone know what would cause a sewer smell in my bathroom just during very cold weather (i.e. under 15 degrees F)? It also happens a little when it rains very hard. Any ideas?
  8 answers
  • This is a common issue in really cold weather. Normally the heat of the water going down the drains tend provide enough lift of the fumes out of the vents on the roof. But in really cold weather they tend to back draft and stick around the vent area. Also when its raining the rain that comes down the pipes push the odors down with the water. Nothing to worry about. Get a dog and blame him for the smells until they subside. One fix if its really bad is if you have access to your attic assuming the pipes are running through it, is to insulate the vent pipes to keep them warmer. This helps with the lift of the fumes and carries them away from the house.
  • Sandra Johnson Sandra Johnson on Jan 26, 2013
    From our experience, it happens in the spring and fall, that rotten egg smell and worse! It may be caused from what is a "turnover" phenomena, like a lake of water "turns" over. The bottom comes to the surface. Why- I can't explain through science. But that is what we've heard.
  • Donna R Donna R on Jan 26, 2013
    Thanks for the replies. I should have searched for the topic even before I posed the question because there is a lot of useful information about this problem. It's funny, but I had the same problem in my last house too. (Must be getting "old-timer's" disease because I forgot all about it!!)
  • Margene Kiefer Margene Kiefer on Feb 05, 2015
    Try pouring Clorx bleach Dow the drain before you go to bed so it can set without more water running to wash it away.
    • Sue Potts Sue Potts on Oct 31, 2015
      @Margene Kiefer Do not ever pour bleach down your drain if you are on a septic tank. The bleach kills your bacteria needed for the tank to function properly.
  • Jacquie van der bijl Jacquie van der bijl on Mar 16, 2015
    Could be grease build up. Puor down some baking soda then vinger. Leave over night and run plenty ofhot water down the drains. Could do the trick.
  • Mes726852 Mes726852 on May 07, 2015
    When your drain trap gets dry it lets the sewer or septic gases come up your drain. If you are not using your tub, shower or sink daily you need to run some water into them to keep a barrier between the gases and your bathroom. I had this problem at my previous home in the basement shower. Summer time was not a problem because my air conditioner unit drained into that shower.
  • Jan Jan on Jul 18, 2015
    Meshelmarie50 is right, keep all the drain traps full of water. You may find its worse whenever the barometric pressure changes. When there's a high, it keeps the gas pushed down, but during a low, like in the winter, stuff comes bubbling up. I had a fancy new house in Germany, with 4 bathrooms, & it kept me running to be sure all the drains had water in them! Grateful I now only have 2!
  • Suzanne Suzanne on Jan 10, 2018

    Thank you for the q and a. Very helpful.