DH04 : No Stall 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 DH0#.

Pump failed the stall test; did not stall on either the upstroke or the downstroke.

  • Replace inlet and outlet valve and seal for up and down strokes. 
  • Replace piston and throat seals. 
  • Replace rod and cylinder as necessary.