Firefighters were called to Burnley General Hospital when a burst pipe caused the renal dialysis unit to flood.
The incident happened at 5-45pm on Sunday when 2-3in. of water poured into the unit.
Martin Morgan, director of Estates and Facilities at East Lancashire Hospitals NHS Trust, said: “There was a problem with a water connection to one of the Renal Dialysis machines on which resulted in a small flood within the unit at Burnley General Hospital.
“The Trust’s maintenance and domestic teams worked closely with the fire brigade and our partners to ensure the connection was repaired and the department was safe to operate and continue normal service today.”
No patients were affected as the service doesn’t operate on Sundays.
Acting crew manager Kev Birchall said: “Firefighters from Burnley attended with the Hazardous Materials Unit and used a specialist pump to remove the water.”