Tecmark 3902-9 Universal Pressure Switch (1-5 PSI)The Tecmark 3902-9 Universal Pressure Switch is a highly versatile, field-adjustable safety switch designed for pool heaters, hot tubs, and spa systems. It acts as a critical safety mechanism, preventing your heating element from operating unless adequate water flow and pressure are detected.Key FeaturesUniversal Application: Engineered to replace a vast range of factory-installed switches, minimizing the need to carry brand-specific parts.Adjustable Pressure Settings: Easily adjusts within a 1 to 5 PSI range to precisely match your equipment's factory flow requirements.Reliable Safety Action: Features a SPST (Single Pole Single Throw) switch configuration that opens the electrical circuit if water pressure drops below the set threshold.Heavy-Duty Construction: Equipped with a durable plastic body and a 1/8" NPT thread connection for a secure, leak-free fit.Product SpecificationsFeatureSpecificationModel3902-9 / Series 3902Pressure Range1 - 5 PSI (Field Adjustable)Electrical Rating1.0 AmpThread Connection1/8" Male NPTTerminals2-Pin Spade ConnectorsMaster Cross-Reference GuideThis universal unit directly replaces original equipment manufacturer (OEM) part numbers from major pool and spa brands, including:Tecmark / Comfortzone: 3900, 3901, 3903, 3904, 3906, 3909, PRS-1100, 1101Laars: R-113, R-130, R-132BRaypak: B600025, 600025Purex: S-19211, 73328Hobbs: M3218, 71076, 26775, 26776, 26777, 26778Ideal ForResolving pool heater "FLO" or flow-related error codes.Replacing brittle, leaking, or unresponsive pressure sensors.Professional HVAC and pool service technicians looking for a single truck-stock solution.