Appendix A-2 - Vent Damper Troubleshooting - Dunkirk DXL-125 Installation, Operation And Maintenance Manual

A.2 Vent Damper Troubleshooting Guide
!
WARNING
Do Not negate the action of any existing safety
orperational controls. Avoidance of 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 maunually 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.
Normal Sequence of Operation
24 VAC
Power ON
Power
4 & 1 All times
4 & 2 Calling for Heat
4 & 3 During combustion
Vent
Damper
Plug
Trouble Shooting
Problem Possible Cause
1. Off on limit (120VAC)
2. Bad transformer
3. Loose or broken connections
NO POWER
Between 4 & 1
4. Blown fuse or circuit breaker
5. Disconnect switch off
6. Harness not plugged into receptacle
NO POWER 1. Thermostat not calling for heat
Between 4 & 2
2. Burned out heat anticipator
3. Loose or broken connections
POWER
4. Off/On opeating limit, pressure control or low water cut off
Between 4 & 1
5. Off/On blocked vent switch or flame roll out
When calling for
heat
POWER 1. Loose or broken connection
Between 4 & 1 2. Defective damper motor
Between 4 & 2
DAMPER OPEN

APPENDIX A-2 - VENT DAMPER TROUBLESHOOTING

Damper Position
Open or Closed
Open or Opening
Damper Open
2 ORG
4 BLK
3 YLW 1 BRN
Recommended Solution
1. turn limit on
2. Replace transformer
3. Tighten, repair, or replace connection
4. Replace fuse or reset circuit breaker
5. Turn switch on
6. Plug harness in
1. Turn thermostat up to call for heat
2. Replace thermostat
3. Tighten, repair, or replace connection
4. Turn operating limit, pressure control, or low water cutoff ON
5. Reset or replace switch
1. Tighten, repair, or replace connection
2. Replace damper motor assembly
28 240009041
P/N , Rev. C [04/30/2017]