Tech Self Help Articles » Nozzle Circuit » Troubleshooting Error 3: Line-Fill Leaks

Troubleshooting Error 3: Line-Fill Leaks

This case is typically caused by what we refer to as a “Line-Fill Leak”. These types of “leaks” are notoriously difficult to troubleshoot because they generally can’t be seen and are difficult to reproduce while on-site. The root cause for these types of leaks is typically leaky fittings. Generally, while testing the system on-site, the tubing will expand under pressure and close off the leak path at the fitting, making it difficult to determine where the leak is coming from.


  • Error 3 on controller/High AFR in Data menu
  • No Visible Leak
  • Difficult to reproduce Error 3 while testing on-site

Record Info and Run Troubleshooting Tests:

1.  Before running ANY mist cycle, record the AFR that caused the Error 3

  • The AFR value can be found by going to the “DATA” menu and looking for “AFR”.
    • AFR stands for the Average Flow Rate (per nozzle) during a mist.
  • Run a short inspection mist cycle until all nozzles are misting, then stop the inspection by hitting the red “MENU” button.
  • Run a manual mist cycle by holding down the “UP” and “DOWN” arrows simultaneously while in the main menu.
  • After completion of the manual mist, check and compare the new AFR to the original AFR that caused the error 3.
    • If the misting unit no longer displays error 3 after the manual mist mist, proceed to Test 2
    • If the AFR remains the same and caused another error 3, proceed to our article on (Leak Diagnosis and Troubleshooting Link).

2.  Reduce Post-Mist HLD (Hold) Time

  • Because this type of leak usually can’t be found on the initial service visit, the following setting that governs error 3 will be adjusted.
    • Find “TOL” in the SETUP menu and adjust it to 100.
  • This adjustment will create a window for the misting unit to operate normally while buying time for the leak to grow and become visible. The unit should eventually encounter an error 3 again, but at that point the leak path should have expanded and be easier to troubleshoot.