PENNCO 15B-060K, Installation, Operation & Maintenance Manual

42

APPENDIX B - VENT DAMPER INSTALLATION

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.

!

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

OPEN

Black

"V" Slot

Yellow

Brown

Orange

Black

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.

Note

Damper wiring harness is made up of 4 

individual colored wires, Brown, Black, Yellow, 

and Orange. See Figure 4.

Check Molex Plugs on Vent Damper Harness:

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.

Do not cut plug off of damper motor assembly 

this will affect warranty coverage.

Figure 4

Verify Molex pins are fully seated in both 

ends of Molex plugs

Figure 5

C.  Remove damper harness from control. Jump Molex   

     connector on control board between two center      

     holes using  

~ 

18 ga. thermostat wire. See Figure 6    

Check Molex Plugs on Vent Damper Harness:

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.

  PN 240012786, Rev. C [11/15/2020]