Chapter Seven: Troubleshooting
Troubleshooting Chart
49
Chapter Seven: Troubleshooting
Troubleshooting Chart
Symptoms
Possible Cause
Remedy
No output or overrange at
zero (after warm-up)
Improper cable
Valve override function
applied
Electronics malfunctioning
Check cable for type
Disconnect valve override
Return for service
Unit indicates a negative flow
Unit installed in gas stream
backwards
Reinstall unit in proper flow
direction
Controller does not track set
point
Improper zero adjustment
Zero meter output, according
to How To Zero the Flow
Controller, page 40.
Controller does not function
Electronics malfunctioning
Valve sticking
Return for service
Readjust the valve, following
the instructions in How To
Adjust the Valve Preload,
page 50.
Oscillation
Too high a controller gain
setting
Incorrect upstream pressure
regulator
Upstream pressure too high
Reduce (turn counter-
clockwise)
Check manufacturers’
specifications
Reduce upstream pressure
Excessive closed conductance
Inadequate valve preload
Readjust the valve, according
to How To Adjust the Valve
Preload, page 50.
Unit does not achieve full
flow
Upstream pressure too low
Excessive valve preload
Increase upstream pressure
Readjust the valve, according
to How To Adjust the Valve
Preload, page 50.
Table 9: Troubleshooting Chart
