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Appendix A-1 - Vent Damper
A.1 Vent Damper Harness - Molex Plugs
WARNING
Do Not negate the action of any existing safety
orperational controls. Avoidance of these instructions
could result in death or serious injury.
!
Note
When servicing controls, all wires must be
labeled prior to disconnection. Wiring errors
can cause improper and dangerous operation.
Do not turn damper open manually or motor
damage will result and void all warranties, use
the service switch.
DO NOT CUT PLUG OFF OF DAMPER MOTOR
ASSEMBLY OR WARRANTY WILL BE VOID.
Check Molex Plugs on Vent Damper Harness:
Note
Damper wiring harness is made up of 4
individual colored wires, Brown, Black, Yellow,
and Orange (refer to drawing below).
1.
Disconnect thermostat wires.
2.
Use the two diagrams below to confirm the Molex plugs
on each end of the damper harness are wired and
operating properly.
Damper end of wiring harness:
A. Hold plug in hand with wiring harness behind Molex
with “V” slot on top. Verify wire colors are in
proper position.
B. Take reading across brown and black wires in Molex
plug, using test meter set for AC volts. 24 volts
should be present.
i. IF NOT, source of the problem is not in
damper; check line voltage and 24 volt supply.
ii. If 24 volts is present across brown and black,
continue to step iii.
iii. Reconnect thermostat wires and turn up heat
setting.
iv. Check voltage across black and orange wires
in Molex plug. 24 volts AC should be present:
• IF NOT, source problem is not the damper.
• If 24 volts is present continue on to step v.
v. Place jumper wire across orange and yellow
wires in Molex plug (see Below). This will
create bypass of the damper, boiler should
then ignite.
• IF NOT, source problem is not the damper. Go to
“Aquastat end of wiring harness’
Brown
Yellow
Orange
Black
"V" Slot
Aquastat End of wiring harness
Hold plug in hand with wiring harness behind Molex with
“V” slot on top. Verify wires colors are in proper position
OPEN
Black
"V" Slot
Yellow
Brown
Orange
Black
A. Remove damper harness from control. Jump Molex
connector on control board between two center
holes using ~18ga. thermostat wire.
i. If boiler ignites, replace damper harness
ii. If boiler does not light, replace control.
• If boiler ignites: Go to section B.2
"Vent Damper Troubleshooting Guide".
NOTE:
Prior to replacing the damper, be sure the
problem is not with wire connections between damper
and wiring harness.
