How to Get Rid of Pesky Shower Drain Smells

A clean home can restore your peace of mind after a long day away, but even if everything appears clean, a lingering odor in the air may indicate an unseen issue hidden in the drain. Shower drains are particularly problematic when it comes to foul odors, and few people are eager to hop into a stinky shower to get clean.

Shower drains can become a source of offensive scents if they are not properly cleaned or there is a problem with the drain system. For instance, if the vent lines are clogged, a vacuum can form inside the drain lines, drying up the water that is supposed to remain in the P-trap and allowing noxious smells to escape. Learn about the factors that can cause foul-smelling drains and how to get rid of the pesky shower drain smells.

Safety Considerations

Fixing a smelly shower drain is usually a job that can be handled by a DIYer, although some problems are best left to a professional. If any of the issues and solutions presented seem beyond your current skills and knowledge, such as how to replace a water heater anode rod, it's a good idea to hire a plumber to assess and rectify the problem.

Before attempting to neutralize a smelly shower drain with chemical products, it's necessary to read the label to identify any potential dangers. In most situations, harsh chemical solutions only mask the odor, so it's important to determine the cause of the foul drain smells before taking action.

Sulfur Bacteria Contamination

When the incoming water comes from a well, the issue of a smelly drain may be due to the water and not the actual drain. Sulfur bacteria can contaminate a well, causing the bathroom, kitchen, or whole house to smell like rotten eggs. If you can't tell whether the issue is the water or the drain, fill up a glass of water and take it outside. If it still smells when you are out, sulfur bacteria is likely the issue.

There are a couple of ways to treat sulfur bacteria, but both should involve a licensed well contractor to avoid creating additional problems. The first option is to shock the well system with a chlorine solution to treat existing bacteria and eliminate the rotten egg smell. However, the bacteria may return after one to two months.

The other option is a more permanent solution, although it costs more. Install a whole-house water filtration system or a well water chlorination system to treat the water regularly.

Soap Scum or Biofilm Buildup

Often, when a drain smells bad, soap scum or biofilm buildup in the drain line is the reason. Biofilm can include a wide range of bacteria and microorganisms that tend to stick together, creating a slimy film that looks similar to mold. These contaminants thrive in dark, damp locations with ample organic matter for the bacteria, making the shower drain an ideal spot to grow.

This problem is one of the easiest to resolve. Use a standard drain cleaner or make a cleaning solution with baking soda and vinegar by pouring the baking soda down the drain and then adding the vinegar. The foamy solution will scour any biofilm that is stuck on the inside of the pipes. After the chemical reaction has stopped, flush the drain with hot water to rinse away any remaining biofilm.

Dirty or Dry P-Trap

The P-trap is a piece of pipe that connects the shower drain to the drain system, although you may be more familiar with the P-trap under the sink. It is easy to recognize because of the P-shaped design. This part of the plumbing traps a small portion of water in the bottom of the P-shaped section to prevent sewer gasses from seeping back up the drain system and into the bathroom.

If the P-trap is dirty, the smells from the drain debris may be causing the bathroom to stink. Cleaning the P-trap with a commercial cleaner or a household solution of baking soda and vinegar should neutralize the odor. However, if the P-trap is dry, there may be a more serious problem.

Sometimes, the P-trap can dry out if the bathroom is not used for an extended period, such as in a guest bathroom. If the shower is used regularly and the P-trap is still dry, it may be due to a blocked vent line. You will need to contact a plumber to assess and fix the issue.

Clogged Drain

Drain clogs may partially or fully block the flow of water and other debris through the drain line. A total blockage is easy to notice because any water poured down the drain backs up into the tub or shower. Partial blockages may allow the water to drain, although it will empty more slowly than normal.

Drain clogs typically consist of hair, soap scum, mineral deposits, oils, and other debris. The longer the clog remains, the more it will start to smell as the various organic compounds gradually break down. If you suspect that the shower drain is clogged, try to clear the drain with a manual drain snake, but if the clog is too big or too deep in the drain line, you may need to contact a professional plumber to clear the drain with a powered drain auger.

Corroded Anode Rod

Minerals in the water can gradually corrode the inside of the water heater, so to prevent the premature failure of the appliance, an anode rod is installed, which attracts iron, limestone, and other minerals or sediments in the water. These particles corrode the anode rod instead of the water heater tank. However, as the anode rod corrodes, it can cause the hot water to smell like rotten eggs.

Fill a glass with hot water and take it outside to determine if the smell is coming from the water or from the drain. If you confirm the odor is coming from the hot water, you may need to replace the anode rod. Experienced DIYers can perform this task on their own, although beginners or those who do not have experience with plumbing systems should contact a professional plumber to handle this repair.

Leaking Drain Pipes

Another problem that can cause the shower drain to smell is cracked or leaking drain pipes. When there is a break between pipe connections or the body of the drain pipe is cracked, the wastewater can seep into the walls, floors, and surrounding insulation. The foul odor of this leaking waste can cause the bathroom and any other affected areas to stink.

The solution to this issue is to locate the leak, repair the pipe, and clean up any areas that may already be contaminated by liquid waste. If the affected areas are not adequately cleaned, mold and mildew can grow inside the floors and walls of the home. Also, remove and replace any wet insulation or damaged drywall.