POST FALLS - A fire that started in the area of the furnace damaged a Post Falls residence and displaced the occupants on Wednesday morning.

The preliminary estimated amount of damage to the residence in the 200 block of East Third Avenue was at least $10,000, said Dan Ryan, Kootenai County Fire and Rescue division chief.

The residence shares the building with a dog grooming business.

"It appears it started with either a furnace or thermostat problem," Ryan said. "The guys who live there said it seemed a lot hotter in the place than it should've been."

Ryan said a fire "flash" was reported in the living room where there was extensive damage, including with furnishings and interior structure.

"The structure outside is still intact," Ryan said.

Both occupants were sleeping and awoke to smoke. The fire was reported at 5:23 a.m.

The occupants were not injured and evacuated before fire crews arrived, but a firefighter suffered an ankle injury during the incident.

Ryan said the occupants both have family in the area to stay with in the interim. He didn't immediately know if the occupants have insurance.

Coeur d'Alene Fire and Northern Lakes assisted KCFR with the incident.

Ryan said the residence did not have a working smoke alarm. It's the second fire in recent days that KCFR has responded to in which the homes didn't have a working alarm.

"Both had the potential to be catastrophic," Ryan said.

The fire at 716 E. 14th on Sunday caused minimal damage thanks to the homeowner being awake and hearing a noise.

With winter here, residents are also encouraged to have their chimneys cleaned and furnaces serviced to decrease the chance of a fire.