Firefighters were called to Barras moor, Perranarworthal on Saturday night after a report of a fire alarm sounding.
Twelve firefighters on two appliances attended the call to a property just after 2am and found smoke in the building.
The occupants of the building had already evacuated and crews entered the building wearing two breathing apparatus, one hose reel and a carbon dioxide extinguisher.
On investigation crews established that the fire was out and was confined to the swimming pool pump.
Fire crews isolated the electrics to the building to make the premise safe.