Hydrolevel 650SV Low Water Cut-Off

The Hydrolevel 650SV Low Water Cut-Off is a heavy-duty, electronic boiler safety control engineered to provide immediate burner circuit interruption during low water conditions. Operating on 120Vac, this Safgard 650 series unit features an automatic reset function that restores power to the burner once the water level returns to a safe operating point. Designed specifically for hot water boilers, the Hydrolevel 45-651 includes the EL1214-SV sensing probe, which is a shorter 3/4" NPT ceramic probe designed to fit into standard reducing tees and tight boiler tappings where space is limited.

Built with a 15,000-ohm sensitivity and a 30-second burner off delay, the 650SV prevents nuisance shutdowns caused by surging or foaming water. The integrated test button allows technicians to verify the burner circuit and control functionality without the need to drain the system or lower the water level. The SPDT switch contacts provide a switching capacity of 5.8 FLA and 34.8 LRA, making this LWCO with short probe a reliable choice for commercial and residential hydronic systems requiring a NEMA 1 enclosure and a maximum pressure rating of 160 psi.

• Enhanced Clearance: The EL1214-SV short probe is ideal for installation in standard black tees and shallow boiler tappings.
• Diagnostic Efficiency: High-visibility LED indicating lights and a manual test button streamline troubleshooting and routine maintenance checks.
• Robust Switching: Features SPDT contacts capable of handling 120V burner circuits and optional low water alarms.
• Durable Operation: No moving parts to hang up or stick, providing consistent electronic water level monitoring.

Can the 650SV be used on steam boilers?
The Safgard 650SV is designed for hot water boilers. For steam applications, a control with a manual reset or specialized timing, such as the 550 or 750 series, may be required depending on local codes.

What is the purpose of the 30-second delay?
The burner circuit lock-out delay ensures that temporary water level fluctuations do not cause short-cycling, protecting the burner components from unnecessary wear.

How do I test the unit without draining the boiler?
Pressing the burner circuit test button breaks the circuit to the burner, simulating a low water condition to confirm the relay is functioning correctly.

Disclaimer: While we strive for 100% accuracy, product data and specifications are subject to change. Please contact our team to confirm compatibility or technical details before purchasing.