Trane heat_pump Error Code 2

What does 2 mean?

Suction pressure below minimum operating threshold for more than 5 minutes.

Common causes

• Refrigerant undercharge - leak in system
• Dirty air filter - restricted airflow
• Frozen evaporator coil
• Faulty TXV metering device
• Extended low ambient operation

Diagnostic & testing steps

1. 1. Connect manifold gauges to measure suction pressure
2. 2. R-410A: expect 115-125 PSI at 75°F return air temp
3. 3. Inspect air filter and evaporator coil for ice
4. 4. Allow coil to defrost if frozen before diagnosing
5. 5. Use electronic leak detector on all refrigerant connections
6. 6. Check TXV superheat: should be 8-12°F

Tools required

• Manifold gauges
• Electronic leak detector
• Thermometer

OEM parts & part numbers

TXV Valve, R-410A Refrigerant, Low Pressure Switch

Part numbers: THT04190, CPT00449, SWT03856

Safety warning

⚠️ R-410A operates at high pressure. EPA 608 certification required.