Vancouver firefighters were called to the Phoenix Inn at 5 p.m. Monday after smoke triggered the fire alarm.
At least four engines and two command cars were called to respond to the hotel, at 12712 S.E. Second Circle, just off Mill Plain east of Interstate 205.
According to radio traffic monitored at The Columbian, Engine 8 arrived to find light smoke in a second-floor hallway, apparently from a malfunctioning heater unit.
Firefighters are investigating, but there are no reports of an actual fire.