What causes sewer gas smells in kitchen sinks?
Sewer gas smells coming from your kitchen sink drain are often caused by a buildup of organic matter or a blockage in the drain pipes. As waste water flows through the pipes, bacteria breaks down the organic matter, releasing sulfur gases that produce a rotten egg smell. If the drain pipes are partially blocked, the gases can back up into your kitchen sink rather than flowing away through the sewer system.
Some common causes of sewer gas smells from kitchen sinks include:
- Food particles, grease, and soap scum building up in the drain pipes
- Partial blockages from accumulated debris, hair, or foreign objects
- Cracked or damaged drain pipes allowing sewer gases to leak in
- A dry p-trap that allows gases to flow back up the drain
- Improperly installed plumbing allowing sewer gas to vent into the kitchen
If you notice the smell coming directly from the drain and intensifying when you run water, it’s likely an issue within the drain itself. A more diffuse sewer gas smell in the general kitchen area may indicate a leak in the plumbing walls or a problem with the main sewer line.
How to get rid of kitchen sink smells from sewer gas
Here are some effective ways to eliminate sewer gas smells coming from your kitchen sink drain:
Pour baking soda and vinegar down the drain
Pouring a homemade baking soda and vinegar drain cleaner down your sink is an easy way to break up grease,food buildup, and other debris. It also helps neutralize stubborn odors. Simply pour 1 cup baking soda down the drain followed by 1 cup vinegar. Let the mixture foam and bubble for 5-10 minutes then rinse with hot water. Repeat weekly or as needed to keep drains fresh. The acidic vinegar reacts with the alkaline baking soda to produce carbon dioxide bubbles that break up gunk.
Use a chemical drain cleaner
For tougher clogs or persistent bad smells, a commercial drain cleaner containing lye or sulfuric acid can help dissolve thick buildup of organic matter. Products like Liquid-Plumr and Drano use caustic chemicals and can be effective for removing blockages. However, they should be used sparingly as they can damage pipes if overused. Follow product instructions carefully.
Flush with boiling water
Boiling water can melt and wash away grease that gets stuck to drain pipe walls. Boil a full kettle of water and carefully pour it down the drain. Avoid splashing as the water will be hot. Repeat a few times a week to keep drains free of buildup. For extra cleansing power, dump a handful of baking soda down the drain before pouring the boiling water.
Use a plunger
Plunging can physically dislodge minor clogs and clear debris from drain pipes. Fill the sink halfway with water, seal off the overflow with a wet rag, then vigorously plunge up and down over the drain opening. The suction can help loosen the blockage. Repeat several times, removing any debris that surfaces. A long snake plunger can reach deeper into drain bends.
Try a salt and ice cubes treatment
For a chemical-free drain cleaner, you can use plain table salt and ice. Pour 1/2 cup salt down the sink and follow with a handful of ice cubes. As the ice melts, the fresh water and grainy salt will wash away residue. The salt also scrubs the drain walls. Do this once a week to refresh pipes.
Use a wire sink scrubber
Threaded sink scrubbers made of plastic or stainless steel are designed to reach down into drains and scrub pipe walls as you plunge them in and out. This physical scrubbing action removes sticky gunk and food buildup. Use with hot water and dish soap, working the scrubber vigorously up and down.
Install a p-trap
If your sink drain setup is missing a p-trap, sewer gas can easily flow back up the pipes. Hire a plumber to install this u-shaped piece of pipe below the sink drain. It will hold water in the bend to create a seal blocking gases. Make sure existing p-traps are filled with water and free of leaks.
Clean the garage disposal
If you have a garbage disposal, run it regularly with cold water to prevent food from sticking to the internal components. Grinding up lemon or orange peels can help freshen the smell. You can also dump 1/2 cup of baking soda and let it sit for 15 minutes before running water through the disposal. Avoid chemical drain cleaners.
Use an enzyme drain cleaner
Enzyme cleaners contain natural bacteria that feed on and dissolve organic material in drains. This both removes blockages and eliminates odors at the source. They are safer for pipes than caustic chemical cleaners. Simply pour down the sink as directed and let the enzymes work overnight. With regular use, enzyme cleaners can keep drains clog-free.
Snake the drain pipes
For stubborn blockages that other methods can’t resolve, use a drain auger or plumber’s snake. Feed the long flexible cable down the drain to physically snag debris and pull it out. Retrieve any loosened material. You may need to snake a drain several times to fully clear a difficult clog. Start with a small hand-crank auger then upgrade to a power drill attachment for deeper blockages.
Install an inline vent
In some cases, a blocked vent stack on your home’s main plumbing can cause sewer gas to bubble up through sinks. Hire a plumber to check vent pipes for obstructions. They may recommend adding an inexpensive Air Admittance Valve inline under the sink as an alternative path for gases to escape the plumbing. This can prevent the gases from releasing into the kitchen.
Seal pipe leaks
If the source of the odor appears to be a leaky drain pipe, try patching small leaks using epoxy putty or a rubber sealing compound. Clean the area thoroughly before applying the sealant. For larger leaks or cracks, the affected section of pipe may need replacing – a job for a qualified plumber.
Trap the gases
For immediate relief from sewer gas smells entering the kitchen, set out shallow containers filled with white vinegar around the room. The vinegar will help absorb and neutralize odors in the air. Activated charcoal or coffee grounds can also trap gases. However, this doesn’t fix the source of the issue which should still be addressed.
When to call a plumber for kitchen sink smells
If DIY remedies don’t eliminate persistent sewer smells coming from your kitchen sink drain, it’s wise to call a professional plumber. A plumber has the expertise and tools to fully diagnose the issue and fix it.
Some signs it’s time to contact a plumber include:
- Bad smells persist after trying multiple home treatments
- You have a visibly cracked drain pipe or leak
- Snaking the drain doesn’t resolve the clog
- The smell seems to come from somewhere other than the drain
- You have very old or damaged plumbing
A plumber can use a drain camera to inspect the pipes and find blockages or damage. They may need to remove sections of pipe to clear out stubborn obstructions. Repairs like replacing worn gaskets, sealing leaks, or installing vents may be required. For severe pipe damage, complete drain replacement may be recommended.
Though a plumbing service call can be costly, it’s often needed to truly solve ongoing sewer gas problems. Many plumbers also offer drain cleaning service contracts on a monthly basis to prevent issues from recurring.
How to prevent future sewer gas smells in the kitchen
Here are some tips to help prevent sewer gas smells from returning to your kitchen sink:
- Install screens over drains to catch food debris and hair
- Don’t pour fats or oils down the sink – these solidify and clog pipes
- Grind food scraps before disposal to avoid buildup
- Use drain strainers in the sink to catch particles
- Pour 1 cup baking soda and 1 cup vinegar down drains monthly
- Use enzyme cleaner regularly to maintain clear pipes
- Ensure any p-traps remain full of water to seal gases out
- Fix any leaks in plumbing fixtures right away
Proper kitchen plumbing maintenance goes a long way towards preventing unpleasant sewer gas smells. However, if you do notice a recurring smell, take action quickly before the issue worsens. Using physical and chemical drain cleaning methods regularly can keep your kitchen sink fresh and odor-free.
Conclusion
Unpleasant sewer gas odors coming from your kitchen sink drain are a common problem but can be resolved with some DIY drain cleaning techniques. Start with baking soda and vinegar treatments, boiling water, or a plunger to remove soft clogs. For severe blockages, stronger solutions like chemical or enzyme cleaners, snaking the drain, or calling a plumber may be required. Preventing future issues relies on staying on top of kitchen drain maintenance and fixing any plumbing leaks early on. With some diligent effort, your kitchen sink can be restored to a fresh, clog-free state.
| Drain Clog Severity | Recommended Treatment Solutions |
|---|---|
| Mild | Baking soda and vinegar treatment, Boiling water, Plunging |
| Moderate | Chemical drain cleaner, Salt and ice cubes, Wire scrubber |
| Severe | Enzyme cleaner, Snaking/Augering, Plumber service call |
