What It Means
- SLP98UHV, SLP99UHV: LSOM - Compressor ran more than 18 hours in air conditioning mode.
- SL297UHNV: LSOM Compressor long run cycle or low system pressure.
Lennox Ducted Heating
Lennox Ducted Heating Error Code E401
Ducted Heating
E401 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 ran more than 18 hours in air conditioning mode.
Models: SLP98UHV, SLP99UHV
How it shows
- Integrated control 7-segment display: E401
Compressor protector is open. Check for high head pressure, check compressor supply voltage. Out- door unit power disconnect is open , compressor circuit breaker or fuse(s) is open, broken wire or connector is not making contact. Low or high pres- sure switch open if present in the system. Compres- sor contactor has failed to close.
Other manual wording
SLP99UHV
Compressor protector is open. Check for high head pressure, check compressor supply voltage. Outdoor unit power disconnect is open , compressor circuit breaker or fuse(s) is open, broken wire or connector is not making contact. Low or high pressure switch open if present in the system. Compressor contactor has failed to close.
Applicable models & manual sources
- SLP98UHV
LSOM − Compressor ran more than 18 hours in air conditioning mode.
- SLP99UHV
LSOM - Compressor ran more than 18 hours in air conditioning mode.
LSOM Compressor long run cycle or low system pressure.
Models: SL297UHNV
How it shows
- Integrated control 7-segment display: E401
Compressor ran more than 18 hours to satisfy a single thermostat demand. Critical Alert. Clears the error after 30 consecutive normal run cycles or power reset. Also monitors low pressure switch trips.
Applicable models & manual sources
- SL297UHNV
LSOM Compressor long run cycle or low system pressure.
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.
