A sprinkler malfunction at the Mount Sinai West emergency room forced the hospital to turn away ambulances for several hours Saturday afternoon.

The sprinkler broke around 3 p.m. and was repaired by early evening, with ambulance arrivals expected to resume by 8 p.m., a hospital spokeswoman said.

Workers could be seen mopping up the flood outside the ER entrance on West 59th Street.

“There was a flood but we’re taking care of it and it’s no big deal,” a security guard said.