Model reference
Lennox L15-65-40
Heat Pump
1 document9 error codes2 service modes
Available documentation
Service Manual
- XPG20 Series Service Literature36 pg
MyPros+ Max
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- Step-by-step diagnostics from the service manual
- Test values, resistance specs, and wiring references
- Verified part numbers when replacement is needed
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Service modes (2)
- Compressor Modulation Operational Check["Turn main power OFF to outdoor unit.","Adjust room thermostat set point above (heating) or below…
- Defrost Board Test Mode["Ensure Y1 input is active (ON) and O line is inactive.","Apply 24V power to the defrost control…
Full entry steps, exit procedures, and test sequences are available in Max.
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