Students and staff at Greenberg Elementary in Northeast Philadelphia were instructed to report to the former Austin Meehan School for in-person learning.
It comes after several days of virtual classes, due to insufficient heat throughout the building.
The move has frustrated some parents, like Sean Gallagher.
"There is no timeline of how long it's going be," Gallagher said. "If it's going be two weeks, the rest of the year, we don't know. That is what we are trying to find out."
The school district did not provide a timeline for repairs, but says transportation will be provided for students.