• Combustion pressure switch check feature and communication interface capability
• Heavy duty electro-mechanical design for long life
• Automatically re-energizes circuit upon return to safe water level
• Equipped with shorter probe for mounting in standard reducing tees
• SPDT switch contact
• Includes shorter EL1214-SV probe suitable for mounting in standard black tee

Hydrolevel B103-30

• Interrupts power immediately in a low water condition
• Provides contacts for optional low-water alarm, heavy-duty construction
• Automatically restarts burner on return of normal water level
• NEMA 1 enclosure

• Burner circuit contacts open after 15 sec delay in a low water condition
• Delay prevents short cycling caused by momentary fluctuations in the boiler water level
• Automatically reactivates burner circuit 30 sec after water reaches the probe, allowing optional water feeder to raise water level above the probe
• SPDT switch contact

Hydrolevel B103-38

• Provides accurate and dependable protection
• External LEDs and simplified wiring for easy
• Probe-style, microprocessor-based control that detects the fluid level in hot water and steam boilers and reacts when the level falls below the minimum safe operating level
• SPDT switch contact

• Automatically shuts off burner in a low water condition to prevent boiler damage
• Heavy duty construction and 16 amp relay suitable for virtually any commercial water boiler needs
• Burner circuit test butTon and interrupts power immediately in a low water condition
• LED indicator lights
• SPDT switch contact
• Includes EL1214-P probe with longer nut for boilers with thicker jackets

Hydrolevel 550P

• Patented adjustable probe sensitivity
• External LEDs and simplified wiring for easy installation and testing
• Includes external test butTon, adjustable delay on break (DOB) and delay or make
• SPDT switch contact

• Provides step-by-step, diagrammed instructions for fast, easy installation and wiring
• Burner circuit locks-out if water remains below probe for 30 sec
• Burner circuit test butTon allows for testing the control without lowering the water level and indicator lights for easy troubleshooting
• SPDT switch contact

• Brass threads provide a metal-to-metal seal that ensures a leak-free installation
• Integrated wrench flats enable secure installation without damage to the housing
• Compact size, easy to install and wire
• Green LED indicates power on
• Red LED indicating low water condition
• Solid state operation
• 15000 ohm probe sensitivity

McDonnell & Miller RB-24

• Patented adjustable probe sensitivity
• External LEDs and simplified wiring for easy
• Probe-style, microprocessor-based control that detects the fluid level in hot water and steam boilers and reacts when the level falls below the minimum safe operating level
• Includes external test butTon, adjustable delay on break (DOB) and delay or make (DOM)
• SPDT switch contact

• 50 VA at 24 VAC pilot duty rating
• 2-1/8" probe
• 30 sec delay on make, 10 sec delay on break
• Features an automatic reset, test switch and LED low water indicator light
• No lock out with loss of power if probe is in water
• Self-cleaning probe
• NEMA 1 enclosure

• 2-1/8" probe
• 30 sec delay on make, 10 sec delay on break
• Features an automatic reset, test switch and LED low water indicator light
• No lock out with loss of power if probe is in water
• Self-cleaning probe
• NEMA 1 enclosure