How can I clear a flow switch error on my display?

What does it mean and what do I have to do to fix it so I can get my machine running?

Flow switch errors can be caused by any of 4 things:

  • Lack of flow
  • Lack of water pressure
  • Flow switch is installed backwards
  • Bad flow switch

What a flow switch is and how it works:

In Ambrell systems, flow switches are mechanical devices placed in a water line, usually containing a plunger and a switch with two electrical positions: open or closed. The plunger operates the switch based on the pressure and amount of water flowing through the switch.

They are rated by gpm (gallons per minute) and psi (pounds per square inch). When there’s sufficient water flow and pressure the plunger moves, and holds the flow switch closed.

All flow switches used in our equipment require a flow differential of 40psi. This means forward pressure, minus back pressure, must be at least 40psi to close a flow switch.

Clearing a water flow error

If the flow or pressure drops below the minimum requirements for your system, you will get the low flow alarms. If the flow and pressure requirements are being met but the alarm is still being set, it’s possible the flow switch has gone bad.

We recommend breaking the water lines and installing pressure gauges and flow meters to be sure the minimum parameters are being met.

If inadequate flow or low pressure are causing the issue, a new flow switch will not resolve the issue and you will have to resolve the supply issues.