Firefighters tackled a blaze at a plant in Gonerby Road, Grantham, last night (Wednesday).
Six crews, from Grantham, Brant Broughton, Corby Glen and Sleaford, and also a hydraulic platform from Lincoln, were called just after 9pm.
A Lincolnshire Fire and Rescue spokesman said there was severe fire damage to a flue extraction unit, moderate heat damage to a plant room and severe damage by smoke to the remainder of the plant room.
The cause was determined to be overheated plant machinery. There were no injuries.