If your electrical flow switch is not commuting, consider the following potential causes and solutions:

• Viscous Fluid: A viscous fluid typically causes early commutation, meaning it occurs at lower flow rates. Try using a larger compensation spring.
• Burnt Sensor: The sensor might have burnt out and become stuck in its last working position, even if no fluid is flowing.
• Low Flow Rate Adjustment: If the switch is adjusted for low flow rates, the shutter may be clogged with dust and dirt. Move the slider to higher flow rates.
• Broken Compensation Spring: A turbulent flow could have broken the compensation spring. Ensure the flow switch operates in a vertical position and that there are no turbulent motions or water hammer effects.