Standardized Ports: Features a 1/2" NPT inlet and outlet for standard black iron pipe connections

Key Benefits for HVAC Professionals Precise Thermal Calibration: Factory-set 175°F Open and 145°F Close thresholds for exact system protection

some models in the 35-65 series feature field-selectable line voltage for 120/240V ignitor options

it provides the precise amperage draw required by the furnace control board to prevent nuisance lockouts or ignition failures

McDonnell & Miller FS5-3/4 Switch R-410A Standardized Ports: Features a 1/2"The McDonnell & Miller FS5 3 4 Flow Switch (Part Number 114760) is a heavy duty, in line solution designed for contractors managing hydronic heating systems and commercial water lines. Built with a robust brass body and EPDM elastomer, this general purpose liquid flow switch provides high reliability low flow rate sensitivity without the need for a secondary pipe tee. It features a single pole, double throw (SPDT) snap acting switch, allowing for