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APPENDIX B - VENT DAMPER TROUBLESHOOTING
B.2 Vent Damper Troubleshooting Guide
WARNING
Do Not negate the action of any existing safety
orperational controls. Avoidance of these in-
structions 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.
Normal Sequence of Operation
24 VAC
Power
Power ON
Damper Position
4 & 1
All times
Open or Closed
4 & 2
Calling for Heat
Open or Opening
4 & 3
During combustion
Damper Open
Vent
Damper
Plug
4 BLK
3 YLW
2 ORG
1 BRN
Problem
Possible Cause
Recommended Solution
NO POWER
Between 4 & 1
1. Off on limit (120VAC)
2. Bad transformer
3. Loose or broken connections
4. Blown fuse or circuit breaker
5. Disconnect switch off
6. Harness not plugged into receptacle
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
NO POWER
Between 4 & 2
POWER
Between 4 & 1
When calling for
heat
1. Thermostat not calling for heat
2. Burned out heat anticipator
3. Loose or broken connections
4. Off/On operating limit, or low water cut off
5. Off/On blocked vent switch or flame roll out
1. Turn thermostat up to call for heat
2. Replace thermostat
3. Tighten, repair, or replace connection
4. Turn operating limit, or low water cutoff ON
5. Reset or replace switch
POWER
Between 4 & 1
Between 4 & 2
DAMPER OPEN
1. Loose or broken connection
2. Defective damper motor
1. Tighten, repair, or replace connection
2. Replace damper motor assembly
Trouble Shooting
