Brochure

Technical Service: 800.742.8368 • fieldcontrols.com 27
TROUBLESHOOTING
Troubleshooting
MILLIVOLT
Troubleshooting Chart: Millivolt
Problem Possible Causes Action
(Continued)
Damper opens and
stops in the open
position but appliance
main burner(s) does
not fire.
Signal voltage between the
Black and Orange wire is
more than 1.5 volts DC.
If voltage between the Black and Orange wire is greater than 1.5 volts
this could cause the motor to overrun the switches. The damper will
open and stop but no signal will be sent to the gas valve to open. If
this is found out to be normal for this gas valve, you need to call Field
Controls Engineering for further assistance.
Damper rotates
continuously.
Defective damper
controller.
Replace controller.
Damper won’t close. Signal voltage at Orange
wire.
Obstruction in damper.
No power or insufficient
power at damper.
Defective damper
controller.
Check for power at controller, only the Black and Brown wires should
be energized. If not, check wiring diagram. The voltage between the
Orange and Black wire must be zero for the damper to close.
Check for protruding screws or binding in pipe/blade assembly and
correct. Because the damper blade rotates in a complete circle, the
damper could open without any obstructions and still get caught on
something when closing.
Make sure that the power to the transformer is still energized.
If all of the above conditions have been checked and the damper still
will not close replace controller.
Damper won’t close
main burner off.
Obstruction in damper. Remove obstruction, because the damper blade rotates in a complete
circle. The damper could open without any obstructions and still get
caught on something when closing.