East Lyme — East Lyme High School will be closed Monday while crews repair a rupture in a pipe serving the building’s heating and cooling systems, Jeffrey Newton, the superintendent of schools, said Sunday night.

Classes at the school, scheduled to serve as a polling place Tuesday, will resume Wednesday, Newton said.

Fire Marshal Richard Morris said a school maintenance worker discovered the rupture shortly before 10 a.m. Sunday. He said inspectors from the state Department of Energy and Environmental Protection visited the site shortly thereafter.

The break in the line caused propylene glycol — a compound used to keep water from freezing — to leak, Morris said.

Repair work will involve draining the entire system, he said.