What It Means
- Outdoor temperature sensor error
Lennox Air handler
Lennox Air handler Error Code 221
Air handler: Air handler (indoor)
Causes & actions from Lennox
How it shows
- Wired controller display: 221
This manual entry does not list further causes or actions.
Applicable models & manual sources
- MMD***M6-1P
Outdoor temperature sensor error
- MMD***S6-1P
Outdoor temperature sensor error
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.
