Hydrolevel 170SV Low Water Cut-Off

The Hydrolevel 170SV Low Water Cut-Off is a heavy-duty safety control engineered specifically for hot water boiler applications. Operating at 120 VAC, this unit effectively prevents burner operation during low-water conditions to protect the heat exchanger from dry-firing damage. It features an automatic reset function that restores burner operation immediately once the water level returns to a safe operating range. The Safgard 170SV is a reliable alternative to the McDonnell & Miller RB-120, making it a versatile choice for service replacements.

This model includes the EL1214-SV sensing probe (Part #45-175), a shorter ceramic-insulated probe designed to fit into standard black iron tees, which simplifies installation in space-constrained piping. The SPDT switch contacts provide a robust switching capacity of 5.8 FLA and 34.8 LRA, and include built-in contacts for an optional external low-water alarm. With a 160 PSI maximum pressure rating and a low 7 VA power consumption, this LWCO is built for long-term durability in both residential and commercial hydronic systems.

• Compact SV Probe: The included EL1214-SV probe is optimized for mounting in standard tees, reducing the need for specialized manifolds.
• Automatic Reset Logic: Eliminates nuisance service calls by automatically restarting the burner when water levels are stabilized.
• Rugged SPDT Switching: High-amperage heavy-duty contacts allow for direct burner circuit integration or external alarm signaling.
• Standard 120V Integration: Designed for seamless 120V boiler control wiring with simple NPT 3/4-inch threading.
• Equipment Protection: Prevents terminal boiler failure by interrupting the safety circuit before critical low-water thresholds are reached.

Does the 170SV require regular maintenance?
The probe-style low water cut-off has no moving parts to clog or stick, though it is recommended to inspect the probe tip annually for scale buildup to ensure accurate sensing.

Can this be used on steam boilers?
No, the Hydrolevel 170SV is specifically calibrated for hot water (hydronic) boilers. Steam units typically require a different sensing delay and reset configuration.

What is the difference between the 170 and 170SV?
The "SV" designation indicates the inclusion of the shorter EL1214-SV probe, whereas the standard 170 may include a longer probe that requires deeper clearance in the tapping.

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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.