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Damper stuck open/closed
What is going on
Possible causes and checks for: damper stuck open/closed.
Likely causes
- At panel: wiring on right terminals
- Zone LED not calling
- Measure damper terminals per A36
- Disconnect stat wires to see if damper goes to normal state — wrong panel output = bad panel. At damper: voltage at motor (trace wire if not), cycle lever by hand (binding linkage/blades/debris), ohm winding (OL = bad motor). p.1002 [976]
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Source: General HVAC service practice — verify per model. Written in our own words; check the manual for your exact model.
For licensed technicians. Gas, electrical and refrigerant work must be done by a qualified, licensed person. Shut off power and gas before servicing, never bypass a safety control, and follow the manufacturer’s manual for the exact model; it and local codes always take priority. HVACopedia is not affiliated with any manufacturer; brand and model names only identify the equipment.