Marley Engineered Products 4520-2059-000 Limit Switch

The Marley Engineered Products 4520-2059-000 is an OEM 160-230F AUTO Limit Switch designed for high-accuracy temperature monitoring in HVAC heating systems. This heavy-duty bimetal disc control serves as a critical safety component, engineered to automatically interrupt the circuit when internal temperatures exceed the 230°F threshold and reset once conditions return to the 160°F range. Frequently utilized in QMark and Berko heaters, this 4520-2059-000 limit switch features a compact, rugged housing built to withstand the thermal stress of industrial air handlers and commercial baseboard units. For contractors performing a furnace limit switch replacement, this genuine Marley replacement part ensures precise thermal overload protection and system reliability. Its snap-action configuration provides a clean electrical break, preventing intermittent arching in high-demand environments. Verify your specific heater model and serial number to ensure a correct fit for this 160-230 degree auto-reset switch during routine maintenance or emergency repairs.

• Precise Thermal Control: Maintains a strict 160-230°F operating window to prevent heat exchanger damage or unsafe cabinet temperatures.
• Automatic Reset Function: Eliminates the need for manual intervention by restoring power once the unit cools to 160°F.
• Industrial-Grade Durability: Constructed with high-quality materials to resist corrosion and vibration in harsh HVAC environments.
• Simplified Integration: Compact footprint and standard terminal connections allow for fast installation in tight cabinet spaces.
• OEM Compatibility: Designed specifically for Marley, Berko, and QMark equipment to maintain original engineering specifications.

• How do I know if my 4520-2059-000 limit switch is failing? If your heater is "short cycling" (turning off before reaching the thermostat setpoint) or if the blower runs continuously while the heating element stays off, the limit switch may be tripped or defective.
• Is this switch a universal fit for all Marley heaters? No, limit switches are calibrated for specific BTU outputs and airflow requirements. Always match the temperature range (160-230F) and part number to your unit's data plate.
• Does this part require a manual reset? No, this is an "AUTO" limit switch. It is designed to reset itself once the temperature drops below the 160°F lower limit.

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.