What It Means
- SLP98UHV, SLP99UHV: LSOM - Compressor short-cycling (Running less than 4 minutes).
- SL297UHNV: LSOM - Compressor short-cycling. .(Running less than 4 minutes). Outdoor unit pressure trip
Lennox Ducted Heating
Lennox Ducted Heating Error Code E403
Ducted Heating
E403 means different things on different Ducted Heating models. Enter your model number to see only your reading, or find your model below.
Causes & actions from Lennox
LSOM - Compressor short-cycling (Running less than 4 minutes).
Models: SLP98UHV, SLP99UHV
How it shows
- Integrated control 7-segment display: E403
Outdoor unit pressure trip. Check dirty coil, fan mo- tor, refrigerant charge.
Other manual wording
SLP99UHV
Outdoor unit pressure trip. Check dirty coil, fan motor, refrigerant charge.
Applicable models & manual sources
- SLP98UHV
LSOM − Compressor short−cycling (Running less than 4 minutes).
- SLP99UHV
LSOM - Compressor short-cycling (Running less than 4 minutes).
LSOM - Compressor short-cycling. .(Running less than 4 minutes). Outdoor unit pressure trip
Models: SL297UHNV
How it shows
- Integrated control 7-segment display: E403
Compressor runs less than 3 minutes to satisfy a thermostat de- mand. Clears the error after 4 consecutive normal run cycles or power reset.
Applicable models & manual sources
- SL297UHNV
LSOM - Compressor short-cycling. .(Run- ning less than 4 minutes). Outdoor unit pressure trip
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.
