Universal Hall Switch Water Flow Sensor for Gas Water Heaters Model: GMFSS19S1 Color: 11 Size: 6 x 40 mm Working Voltage: DC 5V Material: Plastic and Copper Package: Carton Packing Application: Household electric water heater and boiler parts Media Temperature: Normal temperature Function: Water flow switch sensor Key benefits Direct replacement for external water flow sensor assemblies on gas water heaters and boilers. Same shape and size for easy installation. Hall effect switching provides reliable pulse output to the heater control board at low DC voltage (5V). Compact 6 x 40 mm profile fits common mounting positions on household units. Durable plastic housing with copper internal components for consistent electrical connection. What this sensor does Detects water flow and sends a switching signal to the heater control system so the burner or heating element can operate only when water is flowing. Functions as a water flow switch sensor compatible with a wide range of gas water heaters, electric water heaters, and boilers that accept the GMFSS19S1 form factor. Compatibility and installation notes Universal shape and size intended to fit across common brands of water heaters. Verify physical dimensions 6 x 40 mm and DC 5V supply before installation. Designed for normal temperature water applications. Not specified for temperature or special fluid service. Simple replacement component for external flow sensor locations. Packaged in carton packing for and storage. Practical use scenarios a faulty external flow sensor on a household gas water heater to restore burner activation when water flows. Use during routine or refurbishing of electric water heater and boiler units that rely on an external Hall switch flow sensor. Keep as a spare component for service technicians performing maintenance on residential water heating systems. Included information Model GMFSS19S1, 6 x 40 mm, DC 5V, Plastic plus Copper construction, packaged in carton. Note Confirm compatibility with your heater control input and mounting size before .