Responded to a report of carbon monoxide (CO) and an odor in the home. Upon arrival, the Fire Department and Dead River had just completed their inspections. The homeowner, Diana, reported noticing a propane-like odor downstairs earlier in the morning. The Lyme Fire Department detected only trace levels of CO (10 ppm) in the garage and none in the living spaces. My own CO detector read 0 ppm at the boiler while it was operating. Both Dead River and the Fire Department concluded that the odor was likely caused by sewer gases originating from a rarely used bathroom adjacent to the boiler room. I reviewed all boiler safety procedures with Diana, including how to shut off power, water, and oil to the system in the event of an emergency. At this time, the heating system is operating properly and safely.