What It Means
- Limit switch is open and/or high limit has opened three times.
- Sensor communication issue
Lennox Packaged Unit
Lennox Packaged Unit Error Code 4
Packaged Unit
4 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
Limit switch is open and/or high limit has opened three times.
4 models
ZGD036, ZGD048, ZGD060, ZGD074
Packaged HVAC (outdoor)
How it shows
- dsi ignition heartbeat led: 4
This manual entry does not list further causes or actions.
Applicable models & manual sources
- ZGD036
Limit switch is open and/or high limit has opened three times.
ZGD036, ZGD048, ZGD060, ZGD074
Sensor communication issue
8 models
ZCD036, ZCD048, ZCD060, ZCD074, ZGD036, ZGD048, ZGD060, ZGD074
Packaged HVAC (outdoor)
How it shows
- rds red wink led: 4
Check sensor connection. Ensure connection is clean and tight
Applicable models & manual sources
- ZCD036
Sensor communication issue
ZCD036, ZCD048, ZCD060, ZCD074, 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.
What should you check next?
Continue in ACLogics with guided diagnosis for your equipment and symptoms.
