What It Means
- COMPRESSOR 4 NOT OPERATING
Lennox Unit controller
Lennox Unit controller Error Code 203
Unit controller
Causes & actions from Lennox
How it shows
- M4 alarm code: 203
Compressor 4 apparently not operating. Coil temperatures not changing as expected.
Applicable models & manual sources
- MODEL L - M4 UNIT CONTROLLER
COMPRESSOR 4 NOT OPERATING
MODEL L - M4 UNIT CONTROLLER, M4 Unit Controller
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.
