A P-trap is a U-shaped pipe that is installed under a sink to prevent sewer gases from entering the home. The trap is filled with water when the sink is used, and the water forms a seal that blocks odors. Over time, the water in the trap can evaporate, leaving the trap dry and allowing sewer gases to escape. If you notice an unpleasant odor coming from your sink, it's likely due to a dry P-trap.
There are several things that can cause a P-trap to dry out. If your home has high ceilings, the plumbing may be installed too far above the trap, causing the water to evaporate quickly. A leaky faucet or fixture can also cause the trap to lose water. In some cases, homeowners forget to pour water into the trap after using draining cleaners or other chemicals that can damage pipes. Whatever the reason for your dry P-trap, it's important to take action quickly to prevent foul odors from taking over your home.
To refill a dry P-trap, simply pour a gallon of water into the drain. You may need to do this multiple times if your home has high ceilings or if there are multiple fixtures connected to the same drain line. Once you've refilled the trap, run some cold water down the drain for 30 seconds to help keep everything sealed tightly.