I have a rental house that is having a smell emitting mostly from around the entry door. There are hardwood floors that were polyied in 2002, no carpets. It has central air and natural gas heat. The current tenant moved in last June and I noticed she had her windows opened a lot and not running the central air. I went in the unit last week when she complained about the smell and I noticed she had the furnace off. The property was originally a single family house that was duplexed 20 years ago. The other side (separated by a shared original wall) has not had any problems with smells. The other tenant has always run her heating and cooling systems. The smell is sort of a musty to acetone smell. The heat and water heater are natural gas, but it does not smell like gas. There is a sewage clean out in front of her unit, but does not smell like that either. Nor has there been a problem with drains. The roof is water tight, put on in 2002. The house sits under two very large oak trees so it is shaded a lot in summer and not so much when the leaves are off. I am pretty resourseful, but I am not sure who would be best to call in to check this out. One last thing, it does not smell like a dead animal trapped in the wall. The house was built around 1920 and has real stucco exterior walls. No signs of mold or mildew anywhere. The oddity is why would the smell hover mostly around the front entry door? One can even smell it stand outside the door before entering, but only right in front oh the door. Help, Thanks

Some cats and dogs mark their territory on doors. My cat used to do that, rest his soul. Try a good cleaning around the doorway and threshold.

Have you determined the cause? We are having the same problem.

Still not sure of source of the smell. But the tenant moved out to another unit and the smell subsided. I think a contribution to the smell was in her upholstery. She was very "eco-friendly" and may have used some products that caused the odor. She had some old furniture and the fabric may have had some musty odors.