Bosch 87376007810 Flow Sensor

- Monitors water flow through the boiler heating and hot water circuit.

- Signals the control board when flow is present and how strong it is.

- Allows the appliance to fire on demand and modulate output correctly.

- Triggers a safe shutdown if circulation weakens or stops.

- Inline plastic housing spins a small vaned impeller inside the flow tube.

- Sealed sensor module clips to the top of the body and reads impeller rotation.

- Three-wire lead set with keyed white plug connects directly to the existing boiler harness.

- Molded flow direction arrow on the housing side confirms correct orientation.

- Fits between flanged pipe connections.

- Supplied with stainless steel retaining clips, O-rings, and fiber washer.

- Includes mesh inlet strainer for a sealed, complete replacement.

- Alternate part number 8-737-600-781-0.

 

- KWB28-3.

- KWB35-3.

- KWB42-3.

 

The Bosch 87376007810 is a flow sensor that monitors water movement through a boiler's hot water and heating circuit, signaling the control board when flow is present and how strong it is so the appliance can fire on demand, modulate output correctly, and shut down safely if circulation weakens or stops. Water passing through the inline plastic housing spins a small vaned impeller mounted inside the flow tube, and the sealed sensor module clipped to the top of the body reads that rotation and converts it into an electrical signal carried by the three-wire lead set and keyed white plug, allowing the unit to connect directly to the existing boiler harness without splicing. Because the reading depends on water striking the impeller from the correct side, a flow direction arrow is molded into the side of the housing, making the required installation orientation clear when the sensor is fitted between the flanged pipe connections. It is supplied with the stainless steel retaining clips, O-rings, fiber washer, and mesh inlet strainer needed to complete a sealed replacement on compatible boiler models.