I have a septic tank system with newer lines. My home is a 2 story with 1 bathroom on 2nd floor, kitchen and bathroom on 1st floor, and a sink in the garage. Garage sink has an AAV that was installed by a professional. Drains are not slow. When it rains (only when it rains) my upstairs smells like sewer gas. Downstairs occasionally smells like sewer gas from the drains. All drains are used frequently. What is causing the smell in my home?

How are the house fixtures vented? Why were the septic lines replaced? Was a perc test performed on the leach field?

Perc test was done. Lines were replaced because the old ones were clogged. House has 2 roof exhaust vents; 1 close to the downstairs fixtures and 1 towards the upstairs fixtures.

>Downstairs occasionally smells like sewer gas from the drains. All drains are used frequently.
>What is causing the smell in my home?

Sewer gas does not come out of sink drains when the P-traps are properly installed and have standing water blocking the bottom, UNLESS the smell is actually coming from the sink overflow hole. There are cavities inside the sink body to carry overflow water down to the drain. The smell can occur when soap and crud gathers in there over the years. You can test this by duct-taping over the drain and overflow hole of a sink to see if the smell goes away. We had one older sink with this problem, and solved it with a can of Invade Hot Spot. Block the drain lightly so air can escape, spray the whole can into the overflow hole left, right and down. THe pipe will come off, put it back on and keep spraying. The foam should penetrate all the cavities and solve the problem.

Why the whole can? Excess will clean the drain pipes. If you have two problem sinks, one can will do both.



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