Hvac Service Manuals & Error Codes

Service manuals, error codes, and parts diagrams for hvac repair across all major brands.

202Service Documents

56Service Manuals

157Error Codes

9Brands

MyPros+ Max

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Step-by-step tests with expected resistance, voltage, and continuity values
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M+

M+ Max·LG HVAC

1 on my LG HVAC

M+

PCB sees IDU pipe or air thermistor as open or shorted (varies by unit type: Inverter, 10/13 SEER, PTAC).

First step

Ohm thermistor in water, measure water temperature. Pipe=2,800Ω at 38°C/100°F & 10,000Ω at 10°C/50°F. Air=5,600Ω at 38°C/100°F & 20,700Ω at 10°C/50°F. With perfect thermistor & plug connection, change PCB.

Source LG Ductless HVAC & PTAC - Tech Sheet: Error Codes & Wiring

Top Error Codes for Hvac Repair

CodeBrandDescription

1LGPCB sees IDU pipe or air thermistor as open or shorted (varies by...10LGLS902HPV/LS122HPV/LA09xHV/LA12xHV: PCB sees ODU discharge pipe...12LGPCB sees IDU middle pipe thermistor as open or shorted.13LGReactor or electronic noise filter failure in ODU.14LGCompressor Phase Amperage Error.2LGPCB sees ODU or IDU thermistor(s) as open or shorted (varies by unit...21LGInverter compressor high amperage.22LGInverter unit high amperage.23LGInverter DC link voltage too low.24LGHigh or low pressure switch open (low opens at 14 PSI, high at 600...25LGLow voltage or high voltage feeding unit.26LGInverter compressor seized, not rotating or not proving rotation.27LGInverter compressor amperage over 100A for a split second.28LGInverter DC link voltage too low.29LGInverter compressor high amperage.

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Aprilaire Bryant Carrier Lennox LG Rheem Samsung Trane York

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Access 202 service documents, 157 error codes, and step-by-step diagnostics for hvac repair.