About 20 homes were evacuated in Markham, north of Toronto, as a precaution early Saturday, after reports of loud, booming noises in the area.
Fire officials say they were called to a home on Claxton Drive, located in the Main Street and 16th Avenue area, at about 6 a.m.
When crews arrived on the scene, officials say they heard small explosions and noticed fire around a pool heater.
Fire officials say there was an underground gas leak in the line feeding the heater, but the leak has been capped.
Police say no injuries have been reported. Transit buses were brought to the scene to accommodate the evacuated residents.