What It Means
- CBX40UHV: Compressor short-cycling - running less than four minutes.
- 3WPD036S6S-1P: Compressor down due to freeze protection control
Lennox Split & Multi-Split
Lennox Split & Multi-Split Error Code E403
Split & Multi-Split
E403 means different things on different Split & Multi-Split models. Enter your model number to see only your reading, or find your model below.
Causes & actions from Lennox
Compressor short-cycling - running less than four minutes.
Models: CBX40UHV
Air handler (indoor)
How it shows
- Single-character display: E403
This manual entry does not list further causes or actions.
Applicable models & manual sources
- CBX40UHV
Compressor short−cycling − running less than four minutes.
Compressor down due to freeze protection control
Models: 3WPD036S6S-1P
Mini-split unit (outdoor)
How it shows
- mini outdoor inverter pcb: E403
- Mini-split outdoor main board: E403
Check Outdoor Cond.
Applicable models & manual sources
- 3WPD036S6S-1P
Compressor down due to freeze protection control
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.
