F1S3 : Flow Low Purge Pump

To avoid serious injury follow all warnings and instructions in the manual. Wear appropriate personal protective equipment.

The number on the end of the error code refers to which pump is having the issue. For example F1S#.

There has been no flow or low flow during a pump purge operation.


  • Make sure there are no restrictions in the system. Increase non-mix pressure if necessary to create flow during the purge function.