What It Means
- There is a delay in the outdoor unit responding to the system.
- CBK48MVT: There is a delay in the air-handler responding to the system.
- Unresponsive device
- CBX40UHV: Usually caused by delay in outdoor unit responding to indoor unit.
Lennox Split & Multi-Split
Lennox Split & Multi-Split Error Code E120
Split & Multi-Split
E120 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
There is a delay in the outdoor unit responding to the system.
40 models
EL18XCV, EL18XCV-024, EL18XCV-036, EL18XCV-048, EL18XCV-060, EL18XPV, EL18XPV-024, EL18XPV-036, EL18XPV-048, EL18XPV-060, EL19KPV, EL19KPV-024, EL19KPV-036, EL19KPV-048, EL19KPV-060, EL21KLV, EL21KLV-024, EL21KLV-036, EL21KLV-048, EL21KLV-060, EL22KCV, EL22KCV-024, EL22KCV-036, EL22KCV-048, EL22KCV-060, SL22KLV, SL22KLV-024, SL22KLV-036, SL22KLV-048, SL22KLV-060, SL25KCV, SL25KCV-024, SL25KCV-036, SL25KCV-048, SL25KCV-060, SL28XCV, SL28XCV-024, SL28XCV-036, SL28XCV-048, SL28XCV-060
Air conditioner (outdoor), Heat pump (outdoor)
How it shows
- Outdoor control 7-segment display: E120
Typically, this alarm/code does not cause any issues and clears on its own. The alarm/code is usually caused by a delay in the outdoor unit responding to the thermostat. Check all wiring connections. Cleared after unresponsive device responds to any inquiry.
Other manual wording
EL18XCV, EL18XCV-024, EL18XCV-036, EL18XCV-048, EL18XCV-060, EL18XPV, EL18XPV-024, EL18XPV-036, EL18XPV-048, EL18XPV-060, EL19KPV,…
Typically, this alarm/code does not cause any issues and will clear on its own. The alarm / code is usually caused by a delay in the outdoor unit responding to the thermostat. Check all wiring connections. Cleared after unresponsive device responds to any inquiry.
Applicable models & manual sources
- EL18XCV
There is a delay in the outdoor unit responding to the system.
EL18XCV, EL18XCV-024, EL18XCV-036, EL18XCV-048, EL18XCV-060
- EL18XPV
There is a delay in the outdoor unit responding to the system.
EL18XPV, EL18XPV-024, EL18XPV-036, EL18XPV-048, EL18XPV-060
- EL19KPV
There is a delay in the outdoor unit responding to the system.
EL19KPV, EL19KPV-024, EL19KPV-036, EL19KPV-048, EL19KPV-060
- EL21KLV
There is a delay in the outdoor unit responding to the system.
EL21KLV, EL21KLV-024, EL21KLV-036, EL21KLV-048, EL21KLV-060
- EL22KCV
There is a delay in the outdoor unit responding to the system.
EL22KCV, EL22KCV-024, EL22KCV-036, EL22KCV-048, EL22KCV-060
- SL22KLV
There is a delay in the outdoor unit responding to the system.
SL22KLV, SL22KLV-024, SL22KLV-036, SL22KLV-048, SL22KLV-060
- SL25KCV
There is a delay in the outdoor unit responding to the system.
SL25KCV, SL25KCV-024, SL25KCV-036, SL25KCV-048, SL25KCV-060
- SL28XCV
There is a delay in the outdoor unit responding to the system.
SL28XCV, SL28XCV-024, SL28XCV-036, SL28XCV-048, SL28XCV-060
- EL18XCV
There is a delay in the outdoor unit responding to the system.
EL18XCV, EL18XCV-024, EL18XCV-036, EL18XCV-048, EL18XCV-060
- EL18XPV
There is a delay in the outdoor unit responding to the system.
EL18XPV, EL18XPV-024, EL18XPV-036, EL18XPV-048, EL18XPV-060
- EL19KPV
There is a delay in the outdoor unit responding to the system.
EL19KPV, EL19KPV-024, EL19KPV-036, EL19KPV-048, EL19KPV-060
- EL22KCV
There is a delay in the outdoor unit responding to the system.
EL22KCV, EL22KCV-024, EL22KCV-036, EL22KCV-048, EL22KCV-060
- SL22KLV
There is a delay in the outdoor unit responding to the system.
SL22KLV, SL22KLV-024, SL22KLV-036, SL22KLV-048, SL22KLV-060
- SL25KCV
There is a delay in the outdoor unit responding to the system.
SL25KCV, SL25KCV-024, SL25KCV-036, SL25KCV-048, SL25KCV-060
- SL28XCV
There is a delay in the outdoor unit responding to the system.
SL28XCV, SL28XCV-024, SL28XCV-036, SL28XCV-048, SL28XCV-060
There is a delay in the air-handler responding to the system.
Models: CBK48MVT
How it shows
- Single-character display: E120
Typically, this alarm/code does not cause any issues and will clear on its own. The alarm/code is usually caused by a delay in the outdoor unit responding to the thermo- stat. Check all wiring connections. Cleared after unresponsive device responds to any inquiry.
Applicable models & manual sources
- CBK48MVT
There is a delay in the air-handler re- sponding to the system.
Unresponsive device
5 models
EL21KLV, EL21KLV-024, EL21KLV-036, EL21KLV-048, EL21KLV-060
Heat pump (outdoor)
How it shows
- Outdoor control 7-segment display: E120
There is a delay in the system component responding to the system. Typically this alert code does not cause any operational issues and will clear on its own. • This alert code is usually caused by a delay in the outdoor unit responding to the thermostat. • Leaking voltage from strands within the bundle. > Land only the R wire on the R terminal to load the bundle with 24VAC. ► Typically only the R wire needs to be landed to identify if voltage is leaking. ► If voltage is present checking the other wires is informational only but not needed. ► If voltage is not present checking the other wires one at a time would be needed. > Check each loose wire in AC mode to C on circuit board. ► Good voltage is .03 -.3VAC leaking voltage is not the issue. ► Acceptable can be up to .7VAC with moderate success. ► Some units have worked with up to 1.2VAC with occasional success. ► Voltage over 1.2VAC needs to be addressed.
Applicable models & manual sources
- EL21KLV
Unresponsive device
EL21KLV, EL21KLV-024, EL21KLV-036, EL21KLV-048, EL21KLV-060
Usually caused by delay in outdoor unit responding to indoor unit.
Models: CBX40UHV
Air handler (indoor)
How it shows
- Single-character display: E120
This manual entry does not list further causes or actions.
Applicable models & manual sources
- CBX40UHV
Usually caused by delay in outdoor unit responding to 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.
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