The fire brigade were called to Stradbroke High School today after smoke started pouring from a wood chip burner.
They were called at about 10am, and had to force entry to the boiler room.
The situation was under control after contractors were called to repair the boiler.
Sarah Hammond, vice chairman of governors, said there was no fire, no injuries and no damage to the school.
She said: “A fan which extracts smoke out of the chimney failed, resulting in smoke coming from the boiler room door.
“Standard procedure was followed and the fire brigade were called as a precaution. “The fan was replaced today and the school will be open as normal on Monday.”