Lennox LDT078 Error Codes

Packaged HVAC · Packaged Unit

Model numbers in this family: LDT078, LDT092, LDT102, LDT120, LDT152, LHT/LDT078, LHT/LDT092, LHT/LDT102, LHT/LDT120, LHT/LDT152, LHT078, LHT092, LHT102, LHT120, LHT152

• 1 Flash Rollout Switch open
• 2 Flashes Limit Switch open or opened multiple times during one heating demand
• 3 Flashes Pressure Switch open with CAI ON
• 4 Flashes Control lockout - failed to detect or sustain flame
• 5 Flashes Flame sensed and gas valve not energize
• 6 Flashes Pressure Switch closed with CAI OFF
• 7 Flashes Not used
• 8 Flashes Pressure switch opened repeatedly during heating demand
• Blinking Blue Controller is looking for a device to connect to via Bluetooth.
• CLdL Clear Delays
• Fast Flash Normal Operation - call for heat
• Green Controller is powered-up and no Bluetooth devices are currently connected.
• Slow Flash Normal Operation - No call for heat
• Solid Blue Controller still in boot-up state (check7-segment LED) or app is already connected.
• StAt TSTAT Override
• Steady Off Internal control board fault or no power
• Steady On Control board failure
• rSt Reset
• tESt TSTAT Test

Reference only. Confirm against the manual for your exact model. Data release 105f66ecb9e96e5dc473025d.