My home is two stories, 5100 sq feet, and was built in 1990. I have a septic system, radon mitigation, and central forced air.
This has gone on for two winters now, but not before that.
The second story will intermittently smell like sewage (my wife thinks it smells like something died) when the heater kicks on. But the first story and basement don't smell.
- When it does smell, it is almost always in the mornings
- And it seems to happen only when weather outside is cold and the heater is on.
- The smell goes away after an hour even if the temperature outside is below freezing.
- It does not smell during the summer with the air conditioning.
- Mechanical room doesn't seem to smell when this happens.
- Attic doesn't smell when this happens.
- I have checked the blowers for dead rodents and didn't find any.
Does anyone have any ideas as to why this is happening?
Does anyone have any ideas as to how to find/fix the problem?
The issue did turn out to be a dry p-trap located in the mechanical room that we have never used and so I forgot about it.
The reason the smell was only on the second floor is because the p-trap was next the blower that serviced the second floor. The first floor blower was further away and so didn't suck in the sewage smell.
Once I put a cap on the drain pipe, no more smell.