McDonnell Miller Water Level Controls

McDonnell & Miller water level controls are essential safety devices designed to protect both steam and hot water boilers from the severe hazards of low-water conditions. Their primary job is to monitor the boiler’s internal water level and act as an emergency safeguard; if the water drops below the manufacturer’s minimum safe level, the control automatically interrupts the electrical current to the burner to prevent “dry firing.” This prevents dangerous overheating, which can lead to system failure, boiler damage, or even catastrophic rupture. Many models also provide secondary functions, such as triggering low-water alarms or operating automatic water feeders to maintain required levels.