Helen Hunt, head teacher of Caythorpe Primary School, said it had closed on Monday because it had no water.
“We checked all the toilets and water supply and we didn’t have any supply to the school,” she said.
“We had to inform all the parents that the school had shut due to health and safety and sanitation and hygiene issues.”
Lincolnshire Community and Hospitals NHS Group said it was experiencing low water pressure at Grantham and District Hospital, but the supply was still on.
Anglian Water said its website would be updated as the work progressed.
