This is the replacement flow switch for the 1995-1996 Hot Spring Classic, Sovereign, Prodigy and Jetsetter spa models. It is also the replacement for the 1995-1996 Tiger River Manora and Tondi spa models. This low voltage flow switch monitors the flow of water from the circulation pump through the heater and is identified by the blue colored sticker on the switch. Technical Specs: The flow switch is located in the heater interlock relay coil circuit. When the switch is closed (proper flow), voltage is transferred to the heater interlock coil when the control thermostat calls for heat. Activating the relay allows the heater to activate. When the switch is open (low flow), voltage to the heater interlock relay coil is interrupted regardless of the state of the control thermostat. This prevents the heater from activating until the low flow condition has been resolved. This is for 1 Item Troubleshooting: The following are some of the common causes of flow switch tripping; * Dirty or clogged filter * Clogged intake * Low water level * Air lock in the filter canister. * Worn out flow switch (average lifespan is 10-12 years) FLOW SWITCH TESTING 1. Set the meter to 20 volts DC. 2. With the flow switch plugged in and the circulation pump running, meter across the leads on the flow switch cord. 3. The meter should read 0 volts DC. A voltage reading indicates a low flow problem in the flow switch or circuit including wires and connectors. Service Note: The flow switch will shut down the heater only on 1995 & 1996 model Hot Spring Spas. All other functions will remain working in the event of a flow switch trip.