Ace Pelizon Plumbing was called out on an odor/smell. Ace Pelizon Plumbing found two bathtubs customer has not used in an extended period of time. Visually inspected fire place and found it un obstructed. Ace Pelizon plumbing ran water down both tub drains and filled traps with water. Had customer turn on A/C unit that draws air from laundry room area shared wall with fireplace. No smell present at this time. Crawled under home and verified no water or sewage under house causing smell. Explained to customer that plumbing/drains require basic periodic use to keep rubber washer and gaskets from dying out and cracking. Also drain traps under home need to be kept full of water or sewer gas will vent back into home. *this is usually amplified by A/C and heater systems