A Dry P-Trap Might be Why Your Bathroom Smells
A strange sewer-like smell emanating from the bathroom indicates an issue with the plumbing system. If ignored for too long, it poses a safety hazard and causes serious health problems. Therefore, it is critical to track the source of the odor and fix it immediately.
A dried or empty plumbing trap, or P-trap, is one of the first causes to look for when the bathroom drains smell foul, especially if it has been lying unused for long.
What is a P-trap?
The P-trap is a crucial element of the home plumbing system. It is the U-shaped section of the pipe located underneath the sink. Its function is to trap and hold enough water, which acts as a barrier to prevent sewer gases and odors from making their way into the bathroom. A little water remains in the P-trap after someone flushes the toilet, empties the bathtub, or turns off the shower or bathroom faucet.
How do P-traps cause a foul smell?
Some bathroom drains have visible P-traps, such as the one under the sink, while others have a hidden P-trap, like a shower or a toilet. When a bathroom fixture or faucet is not used regularly, the P-trap eventually dries out, allowing the sewer odors to travel up the drain. It happens more frequently during winters.
Along with a regular water supply, P-traps must also have plumbing vent stacks for protection. Without a well-established ventilation system, the drain pipes will need to push and pull air through the P-trap, breaking the preventive water seal and forcing the sewer gas in the bathroom.
Reasons why a P-trap loses water
There are a few factors that might cause the P-trap to have an insufficient amount of water:
The water in the P-trap can evaporate due to excessively dry air conditions.
Oscillation occurs when too much outside air enters the pipe, displacing the water out of the bowl.
When something is stuck inside the pipe and absorbs water from the toilet, a P-trap can empty due to capillary action.
An S-trap, though prohibited throughout the country, can siphon out water from the P-trap. Consider replacing the S-trap if the home is older.
Clogs and leaks are some of the other common P-trap problems that can cause smells to back up inside the bathroom.
How to fix P-trap issues
It is easy to fix a P-trap that ran dry due to a period of inactivity. Flush the unused toilet and pour water down the sink and bathtub drains to restore the P-trap's water barrier. Run water down the infrequently-used bathroom drains regularly to prevent the P-trap from running dry in the future.
If the problem persists, an old or leaky P-trap might be the culprit. Hire a plumbing company to diagnose and fix the issue. A professional plumber can help repair or replace a faulty P-trap and also assist in the quick resolution of other plumbing issues.
Water Wise Plumbing offers Las Vegas area residential plumbing repair for water softeners, sewer lines, water line reroutes ,tankless water heaters, and more. We perform water heater flush, sewer line camera inspection, hydro jetting. Call us today at (702) 605-6408.
