Xylem RB-24SE GuardDog Electronic Low Water Cut-Off for Hot Water Boilers - 24V

The Xylem RB-24SE GuardDog is a 24-volt electronic low water cut-off specifically designed to protect residential hot water boilers from the hazards of low water conditions. This conductance-type safety control immediately interrupts electrical current to the firing device when water levels drop below the manufacturer's minimum safe level, preventing dry firing and potential boiler damage.

Key Features:

• 24 VAC electronic low water cut-off with solid state operation
• Universal wiring harness compatible with 100% of modern residential gas boilers
• Automatic reset feature resumes operation when water level returns to normal
• Test button allows verification of proper operation without lowering water level or removing probe
• Green LED indicator shows power is on; red LED indicates low water condition
• Self-cleaning probe reduces maintenance requirements to every five years
• Brass threads provide secure, trouble-free installation with integrated wrench flats
• Compact design offers improved footprint over legacy RB-24E model

Specifications:

• Voltage: 24 VAC
• Maximum water temperature: 250°F (121°C)
• Maximum water pressure: 160 PSI (11.2 kg/cm²)
• Maximum ambient temperature: 120°F (49°C)
• Threaded connection for easy installation

Important: Not for use on steam boilers or millivolt systems. This model replaces the legacy RB-24E. McDonnell & Miller is a Xylem brand known for engineering comprehensive boiler control solutions for residential, commercial, and industrial applications.