Heat Pump Not Heating

Diagnose Refrigerant Levels and Defrost System Components

Excessive Outdoor Coil Icing

🌡️ DZ20VC0361 20 SEER HP· 2 fixes· 90% success

Reversing Valve Failure

🌡️ DZ20VC0361 20 SEER HP· 2 fixes· 90% success

Replace Defrost Control Board and Test Defrost Sensor with Multimeter

Defrost Cycle Not Initiating

🌡️ DZ20VC0361 20 SEER HP· 2 fixes· 90% success

Compressor Overheating

🌡️ DZ20VC0361 20 SEER HP· 2 fixes· 90% success

Outdoor Fan Motor Failure

🌡️ DZ20VC0361 20 SEER HP· 2 fixes· 90% success

Diagnose Refrigerant Levels and Defrost System Components

Excessive Outdoor Coil Icing

🌡️ DZ17VSS036 3 Ton 17 SEER2 Daikin Fit Side-Discharge Heat Pump· 2 fixes· 90% success

Reversing Valve Failure

🌡️ DZ17VSS036 3 Ton 17 SEER2 Daikin Fit Side-Discharge Heat Pump· 2 fixes· 90% success

Replace Defrost Control Board and Test Defrost Sensor with Multimeter

Defrost Cycle Not Initiating

🌡️ DZ17VSS036 3 Ton 17 SEER2 Daikin Fit Side-Discharge Heat Pump· 2 fixes· 90% success

Compressor Overheating

🌡️ DZ17VSS036 3 Ton 17 SEER2 Daikin Fit Side-Discharge Heat Pump· 2 fixes· 90% success

Outdoor Fan Motor Failure

🌡️ DZ17VSS036 3 Ton 17 SEER2 Daikin Fit Side-Discharge Heat Pump· 2 fixes· 90% success

Diagnose Refrigerant Levels and Defrost System Components

Excessive Outdoor Coil Icing

🌡️ DZ16SA0361 3 Ton 16 SEER Single-Stage Heat Pump· 2 fixes· 90% success

Reversing Valve Failure

🌡️ DZ16SA0361 3 Ton 16 SEER Single-Stage Heat Pump· 2 fixes· 90% success

Replace Defrost Control Board and Test Defrost Sensor with Multimeter

Defrost Cycle Not Initiating

🌡️ DZ16SA0361 3 Ton 16 SEER Single-Stage Heat Pump· 2 fixes· 90% success

Compressor Overheating

🌡️ DZ16SA0361 3 Ton 16 SEER Single-Stage Heat Pump· 2 fixes· 90% success

Outdoor Fan Motor Failure

🌡️ DZ16SA0361 3 Ton 16 SEER Single-Stage Heat Pump· 2 fixes· 90% success

Diagnose Refrigerant Levels and Defrost System Components

Excessive Outdoor Coil Icing

🌡️ DZ14SA0301 2.5 Ton 14 SEER Single-Stage Heat Pump· 2 fixes· 90% success

Reversing Valve Failure

🌡️ DZ14SA0301 2.5 Ton 14 SEER Single-Stage Heat Pump· 2 fixes· 90% success

Replace Defrost Control Board and Test Defrost Sensor with Multimeter

Defrost Cycle Not Initiating

🌡️ DZ14SA0301 2.5 Ton 14 SEER Single-Stage Heat Pump· 2 fixes· 90% success

Compressor Overheating

🌡️ DZ14SA0301 2.5 Ton 14 SEER Single-Stage Heat Pump· 2 fixes· 90% success

Outdoor Fan Motor Failure

🌡️ DZ14SA0301 2.5 Ton 14 SEER Single-Stage Heat Pump· 2 fixes· 90% success

Test and Replace Failed Heat Strip Element

Lennox

38 codes

All Lennox codes

HEAT STRIP FAIL

Supplemental Heat Strip Failure

🌡️ XP25 Dave Lennox Signature Collection Variable-Capacity Heat Pump· 2 fixes· 85% success

DEFROST MALFUNCTION

Defrost System Malfunction

🌡️ XP25 Dave Lennox Signature Collection Variable-Capacity Heat Pump· 2 fixes· 90% success

Test and Replace Defrost Components

REVERSING VALVE STUCK

Reversing Valve Stuck or Leaking

🌡️ XP25 Dave Lennox Signature Collection Variable-Capacity Heat Pump· 2 fixes· 90% success

Replace Reversing Valve Body and Brazing

TXV FAILURE

TXV / Metering Device Failure

🌡️ XP25 Dave Lennox Signature Collection Variable-Capacity Heat Pump· 2 fixes· 90% success

Test and Replace the Thermostatic Expansion Valve (TXV)

DIRTY CONDENSER

Dirty Condenser Coil

🌡️ XP25 Dave Lennox Signature Collection Variable-Capacity Heat Pump· 2 fixes· 90% success

Deep Clean and Straighten the Condenser Coil Fins Using Foaming Coil Cleaner

ALERT 34

Auxiliary / Emergency Heat Active

🌡️ XP25 Dave Lennox Signature Collection Variable-Capacity Heat Pump· 2 fixes· 90% success

Check Refrigerant Charge and Defrost System Operation

ALERT 33

Outdoor Coil Temperature Too Low

🌡️ XP25 Dave Lennox Signature Collection Variable-Capacity Heat Pump· 2 fixes· 90% success

Test and Replace Outdoor Coil Temperature Sensor

ALERT 32

Defrost Cycle Failure

🌡️ XP25 Dave Lennox Signature Collection Variable-Capacity Heat Pump· 2 fixes· 90% success

Test and Replace Defrost Control Board or Sensors

ALERT 31

Reversing Valve Fault

🌡️ XP25 Dave Lennox Signature Collection Variable-Capacity Heat Pump· 2 fixes· 90% success

Test and Replace Reversing Valve Solenoid Coil

3 FLASHES YELLOW

Compressor Thermal Overload

🌡️ XP25 Dave Lennox Signature Collection Variable-Capacity Heat Pump· 2 fixes· 90% success

Test and Replace Compressor Overload Protector

FLASHING GREEN

Normal — Unit Running

🌡️ XP25 Dave Lennox Signature Collection Variable-Capacity Heat Pump· 2 fixes· 90% success

Perform System Diagnostic Check with HVAC Service Tool

ALERT 82

Flame Rollout Switch Open — Furnace

🌡️ XP25 Dave Lennox Signature Collection Variable-Capacity Heat Pump· 2 fixes· 90% success

Inspect and Replace Cracked Heat Exchanger or Flame Rollout Switch

ALERT 75

Liquid Line Temperature Sensor Fault

🌡️ XP25 Dave Lennox Signature Collection Variable-Capacity Heat Pump· 2 fixes· 90% success

Test and Replace Liquid Line Temperature Sensor

ALERT 74

Suction Line Temperature Sensor Fault

🌡️ XP25 Dave Lennox Signature Collection Variable-Capacity Heat Pump· 2 fixes· 88% success

Test and Replace Suction Line Temperature Sensor

ALERT 73

Outdoor Coil Temperature Sensor Fault

🌡️ XP25 Dave Lennox Signature Collection Variable-Capacity Heat Pump· 2 fixes· 90% success

Replace Outdoor Coil Temperature Sensor and Test Wiring

ALERT 72

Indoor Coil Temperature Sensor Fault

🌡️ XP25 Dave Lennox Signature Collection Variable-Capacity Heat Pump· 2 fixes· 90% success

Test and Replace Indoor Coil Temperature Sensor Thermistor

ALERT 71

Outdoor Ambient Temperature Sensor Fault

🌡️ XP25 Dave Lennox Signature Collection Variable-Capacity Heat Pump· 2 fixes· 90% success

Test and Replace Outdoor Ambient Temperature Sensor Thermistor

ALERT 46

Indoor Blower Not Running

🌡️ XP25 Dave Lennox Signature Collection Variable-Capacity Heat Pump· 2 fixes· 85% success

Test and Replace Indoor Blower Motor or Control Board

ALERT 1

Communication Loss — Outdoor Unit

🌡️ XP25 Dave Lennox Signature Collection Variable-Capacity Heat Pump· 2 fixes· 90% success

Test and Replace Outdoor Unit Control Board

HEAT STRIP FAIL

Supplemental Heat Strip Failure

🌡️ XP21 Dave Lennox Signature Collection 20 SEER Heat Pump· 2 fixes· 85% success

Test and Replace Failed Heat Strip Element

DEFROST MALFUNCTION

Defrost System Malfunction

🌡️ XP21 Dave Lennox Signature Collection 20 SEER Heat Pump· 2 fixes· 90% success

Test and Replace Defrost Components

REVERSING VALVE STUCK

Reversing Valve Stuck or Leaking

🌡️ XP21 Dave Lennox Signature Collection 20 SEER Heat Pump· 2 fixes· 90% success

Replace Reversing Valve Body and Brazing

TXV FAILURE

TXV / Metering Device Failure

🌡️ XP21 Dave Lennox Signature Collection 20 SEER Heat Pump· 2 fixes· 90% success

Test and Replace the Thermostatic Expansion Valve (TXV)

DIRTY CONDENSER

Dirty Condenser Coil

🌡️ XP21 Dave Lennox Signature Collection 20 SEER Heat Pump· 2 fixes· 90% success

Deep Clean and Straighten the Condenser Coil Fins Using Foaming Coil Cleaner

ALERT 34

Auxiliary / Emergency Heat Active

🌡️ XP21 Dave Lennox Signature Collection 20 SEER Heat Pump· 2 fixes· 90% success

Check Refrigerant Charge and Defrost System Operation

ALERT 33

Outdoor Coil Temperature Too Low

🌡️ XP21 Dave Lennox Signature Collection 20 SEER Heat Pump· 2 fixes· 90% success

Test and Replace Outdoor Coil Temperature Sensor

ALERT 32

Defrost Cycle Failure

🌡️ XP21 Dave Lennox Signature Collection 20 SEER Heat Pump· 2 fixes· 90% success

Test and Replace Defrost Control Board or Sensors

ALERT 31

Reversing Valve Fault

🌡️ XP21 Dave Lennox Signature Collection 20 SEER Heat Pump· 2 fixes· 90% success

Test and Replace Reversing Valve Solenoid Coil

3 FLASHES YELLOW

Compressor Thermal Overload

🌡️ XP21 Dave Lennox Signature Collection 20 SEER Heat Pump· 2 fixes· 90% success

Test and Replace Compressor Overload Protector

FLASHING GREEN

Normal — Unit Running

🌡️ XP21 Dave Lennox Signature Collection 20 SEER Heat Pump· 2 fixes· 90% success

Perform System Diagnostic Check with HVAC Service Tool

ALERT 82

Flame Rollout Switch Open — Furnace

🌡️ XP21 Dave Lennox Signature Collection 20 SEER Heat Pump· 2 fixes· 90% success

Inspect and Replace Cracked Heat Exchanger or Flame Rollout Switch

ALERT 75

Liquid Line Temperature Sensor Fault

🌡️ XP21 Dave Lennox Signature Collection 20 SEER Heat Pump· 2 fixes· 90% success

Test and Replace Liquid Line Temperature Sensor

ALERT 74

Suction Line Temperature Sensor Fault

🌡️ XP21 Dave Lennox Signature Collection 20 SEER Heat Pump· 2 fixes· 88% success

Test and Replace Suction Line Temperature Sensor

ALERT 73

Outdoor Coil Temperature Sensor Fault

🌡️ XP21 Dave Lennox Signature Collection 20 SEER Heat Pump· 2 fixes· 90% success

Replace Outdoor Coil Temperature Sensor and Test Wiring

ALERT 72

Indoor Coil Temperature Sensor Fault

🌡️ XP21 Dave Lennox Signature Collection 20 SEER Heat Pump· 2 fixes· 90% success

Test and Replace Indoor Coil Temperature Sensor Thermistor

ALERT 71

Outdoor Ambient Temperature Sensor Fault

🌡️ XP21 Dave Lennox Signature Collection 20 SEER Heat Pump· 2 fixes· 90% success

Test and Replace Outdoor Ambient Temperature Sensor Thermistor

ALERT 46

Indoor Blower Not Running

🌡️ XP21 Dave Lennox Signature Collection 20 SEER Heat Pump· 2 fixes· 85% success

Test and Replace Indoor Blower Motor or Control Board

ALERT 1

Communication Loss — Outdoor Unit

🌡️ XP21 Dave Lennox Signature Collection 20 SEER Heat Pump· 2 fixes· 90% success

Test and Replace Outdoor Unit Control Board

Mitsubishi

40 codes

All Mitsubishi codes

Power Transistor (IGBT) Abnormality

🌡️ MXZ-4C36NAHZ 36,000 BTU 4-Zone Hyper-Heat Multi-Zone Outdoor Unit· 2 fixes· 90% success

Replace the Outdoor Unit Inverter Board (IPM Module)

Compressor Startup Failure / Locked Rotor

🌡️ MXZ-4C36NAHZ 36,000 BTU 4-Zone Hyper-Heat Multi-Zone Outdoor Unit· 2 fixes· 90% success

Test Compressor Windings and Replace Faulty Components

Inverter Heat Sink Temperature Too High

🌡️ MXZ-4C36NAHZ 36,000 BTU 4-Zone Hyper-Heat Multi-Zone Outdoor Unit· 2 fixes· 85% success

Replace Faulty Outdoor Fan Motor or Repair Power Module

Electrical Compartment Temperature Too High

🌡️ MXZ-4C36NAHZ 36,000 BTU 4-Zone Hyper-Heat Multi-Zone Outdoor Unit· 2 fixes· 90% success

Replace Electrical Compartment Temperature Sensor and Inspect Wiring

Heat Sink / Power Module Overheat Protection

🌡️ MXZ-4C36NAHZ 36,000 BTU 4-Zone Hyper-Heat Multi-Zone Outdoor Unit· 2 fixes· 85% success

Test and Replace Outdoor Fan Motor or Inverter Power Module

Compressor Overheating / High Pressure Switch Activation

🌡️ MXZ-4C36NAHZ 36,000 BTU 4-Zone Hyper-Heat Multi-Zone Outdoor Unit· 2 fixes· 90% success

Test and Replace Outdoor Fan Motor or Check Refrigerant Charge

Outdoor Heat Exchanger Thermistor Error

🌡️ MXZ-4C36NAHZ 36,000 BTU 4-Zone Hyper-Heat Multi-Zone Outdoor Unit· 2 fixes· 90% success

Check Refrigerant Charge and Inspect for Circuit Restrictions

Compressor Discharge Temperature Protection

🌡️ MXZ-4C36NAHZ 36,000 BTU 4-Zone Hyper-Heat Multi-Zone Outdoor Unit· 2 fixes· 90% success

Power Transistor (IGBT) Abnormality

🌡️ SUZ-KA09NA 9,000 BTU Concealed Duct System Outdoor Unit· 2 fixes· 90% success

Replace the Outdoor Unit Inverter Board (IPM Module)

Compressor Startup Failure / Locked Rotor

🌡️ SUZ-KA09NA 9,000 BTU Concealed Duct System Outdoor Unit· 2 fixes· 90% success

Test Compressor Windings and Replace Faulty Components

Inverter Heat Sink Temperature Too High

🌡️ SUZ-KA09NA 9,000 BTU Concealed Duct System Outdoor Unit· 2 fixes· 85% success

Replace Faulty Outdoor Fan Motor or Repair Power Module

Electrical Compartment Temperature Too High

🌡️ SUZ-KA09NA 9,000 BTU Concealed Duct System Outdoor Unit· 2 fixes· 90% success

Replace Electrical Compartment Temperature Sensor and Inspect Wiring

Heat Sink / Power Module Overheat Protection

🌡️ SUZ-KA09NA 9,000 BTU Concealed Duct System Outdoor Unit· 2 fixes· 85% success

Test and Replace Outdoor Fan Motor or Inverter Power Module

Compressor Overheating / High Pressure Switch Activation

🌡️ SUZ-KA09NA 9,000 BTU Concealed Duct System Outdoor Unit· 2 fixes· 90% success

Test and Replace Outdoor Fan Motor or Check Refrigerant Charge

Outdoor Heat Exchanger Thermistor Error

🌡️ SUZ-KA09NA 9,000 BTU Concealed Duct System Outdoor Unit· 2 fixes· 90% success

Check Refrigerant Charge and Inspect for Circuit Restrictions

Compressor Discharge Temperature Protection

🌡️ SUZ-KA09NA 9,000 BTU Concealed Duct System Outdoor Unit· 2 fixes· 90% success

Power Transistor (IGBT) Abnormality

🌡️ PUZ-HA36NKA5 36,000 BTU Zuba Central Cold-Climate Heat Pump Outdoor Unit· 2 fixes· 90% success

Replace the Outdoor Unit Inverter Board (IPM Module)

Compressor Startup Failure / Locked Rotor

🌡️ PUZ-HA36NKA5 36,000 BTU Zuba Central Cold-Climate Heat Pump Outdoor Unit· 2 fixes· 90% success

Test Compressor Windings and Replace Faulty Components

Inverter Heat Sink Temperature Too High

🌡️ PUZ-HA36NKA5 36,000 BTU Zuba Central Cold-Climate Heat Pump Outdoor Unit· 2 fixes· 85% success

Replace Faulty Outdoor Fan Motor or Repair Power Module

Electrical Compartment Temperature Too High

🌡️ PUZ-HA36NKA5 36,000 BTU Zuba Central Cold-Climate Heat Pump Outdoor Unit· 2 fixes· 90% success

Replace Electrical Compartment Temperature Sensor and Inspect Wiring

Heat Sink / Power Module Overheat Protection

🌡️ PUZ-HA36NKA5 36,000 BTU Zuba Central Cold-Climate Heat Pump Outdoor Unit· 2 fixes· 85% success

Test and Replace Outdoor Fan Motor or Inverter Power Module

Compressor Overheating / High Pressure Switch Activation

🌡️ PUZ-HA36NKA5 36,000 BTU Zuba Central Cold-Climate Heat Pump Outdoor Unit· 2 fixes· 90% success

Test and Replace Outdoor Fan Motor or Check Refrigerant Charge

Outdoor Heat Exchanger Thermistor Error

🌡️ PUZ-HA36NKA5 36,000 BTU Zuba Central Cold-Climate Heat Pump Outdoor Unit· 2 fixes· 90% success

Check Refrigerant Charge and Inspect for Circuit Restrictions

Compressor Discharge Temperature Protection

🌡️ PUZ-HA36NKA5 36,000 BTU Zuba Central Cold-Climate Heat Pump Outdoor Unit· 2 fixes· 90% success

Power Transistor (IGBT) Abnormality

🌡️ PUZ-A18NKA 18,000 BTU P-Series Ducted Heat Pump Outdoor Unit· 2 fixes· 90% success

Replace the Outdoor Unit Inverter Board (IPM Module)

Compressor Startup Failure / Locked Rotor

🌡️ PUZ-A18NKA 18,000 BTU P-Series Ducted Heat Pump Outdoor Unit· 2 fixes· 90% success

Test Compressor Windings and Replace Faulty Components

Inverter Heat Sink Temperature Too High

🌡️ PUZ-A18NKA 18,000 BTU P-Series Ducted Heat Pump Outdoor Unit· 2 fixes· 85% success

Replace Faulty Outdoor Fan Motor or Repair Power Module

Electrical Compartment Temperature Too High

🌡️ PUZ-A18NKA 18,000 BTU P-Series Ducted Heat Pump Outdoor Unit· 2 fixes· 90% success

Replace Electrical Compartment Temperature Sensor and Inspect Wiring

Heat Sink / Power Module Overheat Protection

🌡️ PUZ-A18NKA 18,000 BTU P-Series Ducted Heat Pump Outdoor Unit· 2 fixes· 85% success

Test and Replace Outdoor Fan Motor or Inverter Power Module

Compressor Overheating / High Pressure Switch Activation

🌡️ PUZ-A18NKA 18,000 BTU P-Series Ducted Heat Pump Outdoor Unit· 2 fixes· 90% success

Test and Replace Outdoor Fan Motor or Check Refrigerant Charge

Outdoor Heat Exchanger Thermistor Error

🌡️ PUZ-A18NKA 18,000 BTU P-Series Ducted Heat Pump Outdoor Unit· 2 fixes· 90% success

Check Refrigerant Charge and Inspect for Circuit Restrictions

Compressor Discharge Temperature Protection

🌡️ PUZ-A18NKA 18,000 BTU P-Series Ducted Heat Pump Outdoor Unit· 2 fixes· 90% success

Power Transistor (IGBT) Abnormality

🌡️ MUZ-GL09NA 9,000 BTU Single-Zone Outdoor Unit· 2 fixes· 90% success

Replace the Outdoor Unit Inverter Board (IPM Module)

Compressor Startup Failure / Locked Rotor

🌡️ MUZ-GL09NA 9,000 BTU Single-Zone Outdoor Unit· 2 fixes· 90% success

Test Compressor Windings and Replace Faulty Components

Inverter Heat Sink Temperature Too High

🌡️ MUZ-GL09NA 9,000 BTU Single-Zone Outdoor Unit· 2 fixes· 85% success

Replace Faulty Outdoor Fan Motor or Repair Power Module

Electrical Compartment Temperature Too High

🌡️ MUZ-GL09NA 9,000 BTU Single-Zone Outdoor Unit· 2 fixes· 90% success

Replace Electrical Compartment Temperature Sensor and Inspect Wiring

Heat Sink / Power Module Overheat Protection

🌡️ MUZ-GL09NA 9,000 BTU Single-Zone Outdoor Unit· 2 fixes· 85% success

Test and Replace Outdoor Fan Motor or Inverter Power Module

Compressor Overheating / High Pressure Switch Activation

🌡️ MUZ-GL09NA 9,000 BTU Single-Zone Outdoor Unit· 2 fixes· 90% success

Test and Replace Outdoor Fan Motor or Check Refrigerant Charge

Outdoor Heat Exchanger Thermistor Error

🌡️ MUZ-GL09NA 9,000 BTU Single-Zone Outdoor Unit· 2 fixes· 90% success