Sewage Smell in the House? 6 Sources and How to Find Them

Sewer gas isn't just unpleasant — methane and hydrogen sulfide are unhealthy in a closed house. Here's where the smell usually comes from, in order of likelihood.

1. Dry P-trap

Every drain has a U-shaped trap that holds water to block sewer gas. A guest bathroom or floor drain that hasn't been used in weeks dries out. Run water for 30 seconds. Fixed? That was it.

2. Failed toilet wax ring

If the toilet rocks or the smell is strongest near its base, the wax seal has failed and gas is escaping under the toilet. That's a quick toilet repair.

3. Blocked plumbing vent

Drains gurgle and the smell comes and goes. Debris on the roof vent traps gas inside.

4. Cracked or broken sewer line

Smell inside and out, soggy or unusually green patches in the yard, slow drains throughout. Only a sewer camera inspection confirms this.

5. Biofilm in drains

Bathroom sink and shower drains grow a stinky biofilm. Professional drain cleaning removes it.

6. Water heater

If the smell is only in hot water, sulfur bacteria are reacting with the anode rod. A rod replacement usually solves it.

If you smell sewage and drains are backing up, treat it as an emergency and call us 24/7.

Need it fixed today? Call Crosby Plumbing Inc at (888) 809-6756 — 24/7, anywhere in Florida.