Overview:
Possible Causes (1-22)
1. Supply fan fail
2. Zone temperature sensor input failure on CV units
3. Programmable ZSM communication failure
4. Manual compressor lockout (one or both circuits)
5. Outdoor coil temp sensor failure (heat pumps only)
6. Defrost fault condition (heat pumps only)
7. Gas heat failure
8. Discharge air temperature failure on modulating heat and modulating reheat units
9. Frostat active
10. Outdoor air temperature sensor failure
11. Smoke detector active
12. Entering evaporator temperature failure (on modulating reheat units)
13. RTOM communication failure
14. RTDM communication failure (on modulating reheat units)
15. RTVM communication failure
16. Space pressure sensor failure
17. Dehumidification mis-configuration
18. Reheat circuit entering evaporator temperature failure
19. Zone temperature sensor failure during unoccupied mode and on units with modulating reheat (VAV
only)
20. Static pressure transducer output failure (VAV only)
21. High duct static pressure trip (VAV only)
22. Discharge air sensor failure (VAV only)
WARNING:
Information in this article is intended for use by individuals possessing adequate backgrounds of electrical and mechanical experience and who comply with all federal, state, and local laws, rules, orders, or regulations related to the installation, service, or repair of a heating or central air conditioning product. Any attempt to install, service, or repair a heating or central air conditioning product may result in personal injury and/or property damage. The manufacturer or seller cannot be responsible for the interpretation of the information contained herein, nor can it assume any liability in connection with its use.