If a drain emits foul sewer odors despite flowing freely, the issue is typically caused by a dried-out P-trap, a dirty overflow port, or decomposing organic slime lining the interior pipe walls. Pour a large pitcher of water down the drain to replenish the water seal inside the P-trap. For organic slime, pour half a cup of baking soda followed by white vinegar down the drain, let it fizz for 30 minutes, and scrub the overflow opening with a small brush. Verification: Pour a cup of water down the drain to confirm the P-trap seal is full and odor-free.
1 votes
Marked as accepted