ECR International Dunkirk WPSB 3 Series Installation, Operation & Maintenance Manual page 33

B.3 Vent Damper Harness - Molex Plugs
!
WARNING
Follow all instructions regarding safety operational
controls in this manual. Failure to follow these
instructions could result in death or serious injury.
When servicing controls, all wires must be
Note
labeled prior to disconnection. Wiring errors
can cause improper and dangerous operation.
Do not turn damper open manually or motor
damage will result.
Do not cut plug off of damper motor assembly
this will affect warranty coverage.
Check Molex Plugs on Vent Damper Harness:
Damper wiring harness is made up of 4
Note
individual colored wires, Brown, Black, Yellow,
and Orange. See Figure 4.
1.
Disconnect thermostat wires.
2.
Confirm the Molex plugs on each end of the damper
harness are wired and operating properly. See Figures
4 and 5.
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 Figure 4). This will
create bypass of the damper, boiler should
then ignite.
• If boiler ignites: Go to section B.4 "Vent
Damper Troubleshooting Guide".
• If boiler does not ignite: Problem is not the
damper. Go to Damper harness Molex on
Aquastat, Step C.
NOTE: Prior to replacing the damper, be sure the
problem is not with wire connections between damper
and wiring harness.
APPENDIX B - VENT DAMPER INSTALLATION
Figure 4
Verify Molex pins are fully seated in both
ends of Molex plugs
Figure 5
Control 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
"V" Slot
Black
OPEN
Check Molex Plugs on Vent Damper Harness:
C. Remove damper harness from control. Jump Molex
connector on control board between two center
holes using ~ 18 ga. thermostat wire. See Figure 6
i. If boiler ignites, replace damper harness
ii. If boiler does not light, check for 24 volts at
B1-B2 on aquastat. If no replace control.
iii. If 24 Volts are present Damper and Control
are ok. Check ignition module, rollout switch,
spill switch or gas valve.
Figure 6 Figure 6
33
Yellow
Orange
Blue
"Circ Delay"
Light
Jumper two
center pins
PN 240013090 REV. C [10/01/2021]
Brown
Black