Sir Robert Pattinson Academy will be closed tomorrow for Year 7, 8 and sixth form pupils due to a heating failure.
A letter has been sent home to parents from headteacher Helen Renard explaining that a faulty boiler has left part of the North Hykeham academy without any heat.
"The action taken to remedy this today has been unsuccessful, although commissioning of a new boiler tomorrow should ensure we are open as normal on Wednesday December 5," said Mrs Renard in the letter.
"If you are unable to provide a safe place for your son or daughter on Tuesday, we can provide limited accommodation in the academy.
"Any member of Year 7 or 8 who has to come into the academy on Tuesday must report to the main hall for registration and should bring a book or books to read.
"I apologise for any inconvenience this may cause and can assure you we have done our utmost to rectify the problem today."
The school will be open and buses will be operating as normal for the other year groups.