Sump Pump Odors – How to Detect & Eliminate Issues

By HomeAdvisor

Updated September 8, 2017

How to Get Rid of Sump Pump Odors
Sump pumps are lifesavers. If you live in an area with a lot of moisture or a high water table, your basement is always at risk for flooding, but a quality sump pump redirects any incoming water away from your home’s foundation.

However, like all technology, these machines sometimes run into difficulties. They work almost all year round, sometimes for several hours a day (if there’s heavy rainfall), and so they put up with a lot of abuse. They should work for about 10 years without replacement, but in the meantime they may require occasional maintenance. Here are some common questions you may encounter:

What Can I Do about Sump Pump Odor?

Like any drain, your pump has a trap that holds water in order to prevent sewage gas from backing up and entering into the home. If you’re going through a dry spell and this drain has not been used for two or three weeks, the water in the trap has evaporated, allowing the gas to escape, thereby creating sump pump m

So it’s important to make sure there is always a least a little water in the trap at all times: just enough to cover the outgoing pipes and drain lines. To get rid of the smell though, concoct a diluted bleach solution (about one cup per gallon) and pour it into the basin until the float switch activates. Plus, scrubbing down the sides of the basin will help eliminate the smell.

But My Sump Pump Doesn’t Run At All?

First, see if it is plugged in. It may sound silly, but you’d be surprised how many times the plug gets disconnected due to the machine’s shifting vibrations or the water’s ebb and flow. Next, because these appliances tend to use their own circuits, check for blown fuses. Since they’re located near water, you’ll probably have a GFI switch, so see if it has tripped as well. Or it may work, but it just hasn’t had a chance: if it’s been dry for a few weeks, pour water into the well to see if simply needs to be primed.

What If It Runs but It Doesn’t Remove Water?

The easiest solution is to test the float. See if it is stuck on something that’s impeding its activation: sump pumps often shift and settle so moving parts can often get tangled. Next, lift it out, remove its housing, and clear the screen. Since it’s sitting at the bottom of a basin, sand, mud, rocks, and other debris may be trapped inside and impairing the impellor.

It may be a good idea to set the apparatus slightly above the well floor, such as on bricks, and clear out the bottom so that there is less risk of future clogging. There could also be a clog somewhere else (such as in the discharge lines) or the drainage pipes could be air-locked, which means they’ll need to be properly ventilated by a professional.

What If My Power Goes Out?

The biggest problem with sump pumps is electrical outage. In a thunderstorm, water is constantly coming into your basement, but when the power goes out, it also turns off the one machine keeping your house dry. It’s recommended you invest in a battery backup system: these gel-packs feed power to the pump so it can work for days without electricity from your main power source. It’s great for when you’re out of town during an outage: there’s nothing worse than coming home from vacation to a swamped basement.

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How Do I Know If It’s the Right Size?

The other biggest sump pump problem comes with improper installation, so always call a trained plumber who has adequate experience with these specialized pieces of equipment. It may cost more but they can supply quality products with guaranteed installation (and they should always offer warranties to back this up).

Plus, they’ll know which size works best for you: it’ll usually be 110 volts or 1/3 horsepower, but it depends on your situation. Also, they’ll know if the basin is the right size: it should be at least 2 feet across and 20 gallons in volume (any smaller and it’ll constantly run or increase risk for entanglement).

If these simple repairs don’t do the trick, the sump pump problems may be complicated. It doesn’t necessarily mean replacement, but it does mean a professional plumber is needed. It may be that your drainage lines or pipes, your septic system or your tiling. These more in-depth repairs should be left to the experts. So when calling on technicians, make sure you have information ready for them: check the manufacture’s warranty, get the model number, and any other appropriate information they may need in order to help.


  1. Jan, October 19:

    Once you have put the water and bleach in the pump and the float switch has started to empty, do I leave the remaining water/bleach that is left in the pit (it does not empty entirely). Will it cause any damage just sitting in the pit with bleach?

  2. Karman, November 1:

    What does itmean when my sump pump runs all the time?

  3. scott, December 17:

    we had the float replaced a few years back.i think the pump is incorrectly connected to the basement suite toilet and sink……not for ground water….could this be why it smells so bad??

  4. Laura Childs, January 7:

    My sump pump does not drain all of the water. The water from a basement shower and the water from the washer goes through the sump pump. I have emptied the water and scrubed the sump pump. I have an ordor from the water that is left standing in the sump pump so my question is what can I put into the water to take away the sewer smell. Thanks

  5. Nycole, January 27:

    When ice thaws (spring time) our house smells like rotten vegetation. Pump is next to Heater. What do I do?

  6. Milli, March 15:

    We have an odor from our sump pump that comes on very quickly at odd times. It is not a sewer smell, more like stagnant water. Very strong odor! We have a shower and a washing machine which goes into it. We also have a drainage system around the walls of the basement which empty into the sump pit. I try to keep the water very clean and we flush it out 2 to 3 times a week. I also put bleach in it and we have scrubbed the pit out. We are beside our selves trying to figure out where this odor is coming from, Any suggestions?

  7. jere Heine, June 3:

    does old houses need a sump pump installed? what year did they start putting it in? I was told that many where grandfathered in, not requiring a sump pump

  8. Donna, August 11:

    We also have the same problem with smells from the sump pump. Our washing machine and shower also drains into it. I put bleach in it, have scrubbed it and empty it ever time it is close to the top. Still stinks. There is a slimy looking mess in the drain pipe that I think is from the shower. Any suggestions?

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