Hanna Instruments Flow Switch for BL10x / BL12x / BL13x Controllers (FLOWSWITCH)

Hanna Instruments flow switch for BL10x / BL12x / BL13x controllers (FLOWSWITCH)

The FLOWSWITCH is a flow-detection safety switch designed for use with Hanna Instruments BL10x, BL12x and BL13x series pool and spa controllers. It is fitted in the circulation line and signals the controller whether water is actually moving past the measuring point. When flow stops, the controller can interrupt dosing so chemicals are not injected into a static pipe.

What it fits

This flow switch is intended for Hanna Instruments controllers in the BL10x, BL12x and BL13x families, including the pH, ORP and chlorine dosing models used in commercial pool water treatment. It connects to the dedicated flow-switch input on the controller. Check the terminal layout of your specific model before wiring, as input positions differ between generations.

Installation position

The switch is installed in the circulation or bypass line, upstream of the injection point and close to the probe holder so it senses the same water the sensors measure. Mount it according to the flow direction marked on the body and make sure the line is fully flooded during normal operation. Wire the two contacts back to the controller’s flow input following the controller manual.

Service life

A flow switch is a mechanical part and the moving element can be slowed by scale, biofilm or debris in the water. Test its operation periodically by closing the bypass valve and confirming the controller reports a no-flow condition. Replace the unit if it fails to switch reliably, sticks in one state, or shows housing leaks.

Ordering notes

Sold individually as a single flow switch, not as a complete bypass or probe-holder assembly. Fittings, unions and cable extensions are not included and should be ordered separately if required. Confirm your controller model reference before ordering to avoid an incompatible input configuration.