Sewer smell in basement
We recently finished our walk out basement. In the process of finishing the basement we added a new bathroom and laundry. So the plumbing contractor installed new drain lines and repaired a collapsed floor drain. Air admittance valves were installed.
My question is can these valves fail. Because there are 3 installed, one in the laundry room, one in the bathroom under the sink and another at the intersection of the main waste line and new toilet waste line in the utility area by the furnace. Since these valves were installed, I now get a strong sewer smell in the utility area. However the smell is only present when the air conditioning has been running for extended periods of time. The rest of the time, there is no smell, even when the furnace is running. And I would not assume it would be from the floor drain because we have a radon tight drain cover.
Any thoughts on why this is happening would be greatly appreciated.
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