The explosion at the Luther Park home of the Gloria Dei complex in Upper Moreland Township was reported shortly after 2 p.m. Tuesday.
Fire Marshal Bob Drennen told The (Doylestown) Intelligencer that 73 patients, most of them in wheelchairs, were taken to another building on the grounds.
Drennen said the facility had been running on a generator at the time of the blast. He said that when firefighters arrived, flames were shooting high into the air and touching the side of a wing of the home.
The patients were able to return to the facility later that afternoon. There were no reported injuries.
Information from: The Intelligencer