Fixing Bad Odor from Dry Traps in Plumbing Drains

Do you have an unused drain that is emitting a horrible stench? Most drains have a trap that fills with water and prevents sewer gases from escaping up the drains and back into your home.  Those drains that are not often used such as basement floor drains or extra bathrooms may dry out from non-use and have a dry trap. This means those nasty sewer gases can come up through the drain and into your home. If you are experiencing a smelly drain in your home, you might be able to fix the issue by simply adding moisture and sealing your drain trap.

If you have a drain that is emitting odor and has not been used in some time, simply run water down the drain for a few minutes. This will flush out any debris and refill the drain trap with water. However, if left unused, the water will once again evaporate and you will have the same issue. Try adding a small amount of vegetable oil, just a few tablespoons, after the water has finished draining. This oil will float on the top of the drain trap water and help prolong the drain from becoming dry by slowing evaporation.

However, not all bad odors are due to a dry trap. There may be something more serious happening in your sewer pipes. If you try eliminating the dry trap and there is still a bad odor, it is time to call a plumber. You may have a clog forming in your sewer pipes that is causing the smell. Your local plumber can investigate the issue using digital video cameras or other methods and offer a solution.

Posted on behalf of:
Kiddco Plumbing Inc
Sterling, VA
(703) 435-4441

Sewer Gas Smells

If you have noticed an unpleasant smell in a bathroom or elsewhere in your home but can’t track down the source, it can be a sign of a serious sewer or septic problem that needs the attention of an experienced professional plumber.  It’s possible you have leaking or broken drain line, or a broken sewer vent line.  But there may be a simple answer to bathroom odors that are hard to track down – a dry trap.

Plumbing traps are curved sections of drain pipe that are designed to hold a little water and prevent sewer gas smells from entering your home through the drain pipe.  The easiest place to see a plumbing trap is under the bathroom or kitchen sink.  You will see a curved section of pipe just under the sink.  This section of pipe is often called a “J trap” or “P trap” because it’s shaped like a J or a sideways P.

These plumbing traps are installed on every drain in your home including sinks, showers, tubs, utility sinks, washing machine drains, and so on.  The lowest section of the pipe holds water that prevents the sewer gas smell from your sewer or septic system from backing up through the pipe and entering your home.

However, if the drain is not used for a long period of time, the water can evaporate and allow sewer gas into your home creating a sulfer or rotten egg smell. Many homes have bathrooms that are rarely used such as in a guest bedroom and this is a very common source of sewer gas smells.

To solve the problem, simply run some water down the drain.  The plumbing trap will fill with water and stop the smell.  In addition to the unpleasant odor, sewer gas is also dangerous so it’s important to track down the source and fix the problem.  If the source of the smell turns out not to be a dry trap, call a professional plumber right away.