What It Means
- No response error address from indoor unit
Lennox Air handler
Lennox Air handler Error Code 109
Air handler: Air handler (indoor)
Causes & actions from Lennox
How it shows
- Wired controller display: 109
This manual entry does not list further causes or actions.
Applicable models & manual sources
- MMD***M6-1P
No response error address from indoor unit
- MMD***S6-1P
No response error address from indoor unit
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.
