Mentioned once already but....
Add water to all your drains. Every drain has a trap in it. The trap holds water to keep sewer gas from coming back up the drain. If it's not coming from a drain, then check the vents. These should be on the roof as small tubes and vent the gas from the drains to the roof. If clogged with something, bird nest, etc. it could be coming out somewhere else.
With a 2-yr old house, you could still have paint, adhesives, or putty causing the odor. I doubt it is propane.
Jon, I have a small chest-of-drawers that I bought unpainted many years ago. I stained and finished the chest myself. Problem is, it stinks. It's not a strong odor, but when you close up a room with it in it, the odor of the wood or the finish is very evident when you enter the room. With a 2-yr old house, you could still have paint, adhesives, or putty causing the odor. I doubt it is propane.
Mentioned once already but....
Add water to all your drains. Every drain has a trap in it. The trap holds water to keep sewer gas from coming back up the drain. If it's not coming from a drain, then check the vents. These should be on the roof as small tubes and vent the gas from the drains to the roof. If clogged with something, bird nest, etc. it could be coming out somewhere else.
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