What It Means
- Power-up self-discovery unit code 78 for EL19KPV-048 heat pump.
Lennox Split & Multi-Split
Lennox Split & Multi-Split Error Code 78
Split & Multi-Split: Heat pump (outdoor)
Causes & actions from Lennox
How it shows
- Outdoor control 7-segment display: 78
Unit Code: 4-TON HEAT PUMP EL19KPV-048
Applicable models & manual sources
- EL19KPV-048
Power-up self-discovery unit code 78 for EL19KPV-048 heat pump.
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.
