What It Means
- Incompatible sensor installed
- Prove switch open or closed or rollout switch open.
Lennox Packaged Unit
Lennox Packaged Unit Error Code 3
Packaged Unit
3 means different things on different Packaged Unit models. Enter your model number to see only your reading, or find your model below.
Causes & actions from Lennox
Incompatible sensor installed
8 models
ZCD036, ZCD048, ZCD060, ZCD074, ZGD036, ZGD048, ZGD060, ZGD074
Packaged HVAC (outdoor)
How it shows
- rds red wink led: 3
Replace sensor
Applicable models & manual sources
- ZCD036
Incompatible sensor installed
ZCD036, ZCD048, ZCD060, ZCD074, ZGD036, ZGD048, ZGD060, ZGD074
Prove switch open or closed or rollout switch open.
4 models
ZGD036, ZGD048, ZGD060, ZGD074
Packaged HVAC (outdoor)
How it shows
- dsi ignition heartbeat led: 3
This manual entry does not list further causes or actions.
Applicable models & manual sources
- ZGD036
Prove switch open or closed or rollout switch open.
ZGD036, ZGD048, ZGD060, ZGD074
Disclaimer: This information is for general reference. Code wording and instructions vary by model. Always follow the service manual for your exact unit.
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