Reznor 93849 Pressure Switch

The Reznor 93849 Pressure Switch is a critical OEM replacement part designed for precise combustion air proving across a wide range of Reznor unit heaters and duct furnaces. This low pressure switch monitoring component is engineered as a normally open (NO) safety device that closes upon detecting sufficient negative pressure from the venter motor, ensuring the ignition sequence only proceeds when proper venting is established. Built for high-reliability in demanding commercial and industrial environments, the 93849 HVAC switch features standard 1/4-inch and 3/16-inch quick-connect terminals for a secure electrical interface with the system's control board.

As a veteran technician, you know that unit heater troubleshooting often points to the pressure switch when the venter motor runs but the burner fails to ignite. This switch is calibrated for specific differential pressure set points required by Reznor’s engineering standards to safeguard against blocked flues or motor failure. The compact, robust housing is designed for direct-fit installation, reducing downtime during emergency service calls. By utilizing an authentic Reznor 93849, you ensure the furnace maintains its safety listing and operates at peak pneumatic efficiency without the risks associated with universal "one-size-fits-all" components.

• Authentic OEM Specification: Guaranteed compatibility with Reznor heating equipment, maintaining the integrity of the original safety circuit.
• Precision Combustion Air Proving: Accurately senses the required airflow to allow safe burner operation and prevent hazardous drafting conditions.
• Quick-Connect Interface: Features standard terminals for rapid field installation and reliable electrical continuity.
• Industrial-Grade Durability: Engineered to withstand the thermal cycling and vibration typical of exhaust venter assemblies.

Is the Reznor 93849 a direct replacement for older sail switches?
Yes, in specific RPV series and older duct furnace models, this pressure-activated switch is used in official kits to upgrade or replace legacy sail switch mechanisms for more reliable airflow detection.

What causes this switch to fail to trip?
Common issues include cracked silicone furnace tubing, a clogged collector box port, or a failing venter motor that isn't pulling enough WC (Water Column) pressure to meet the switch's set point.

Can I adjust the pressure set point on this model?
The 93849 is factory-calibrated for specific safety thresholds. Field adjustments are not recommended as they can compromise equipment safety; if the switch does not close at the rated pressure, it should be replaced.

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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.