Display shows “LP” and the unit will not heat; compressor attempts to start but shuts down shortly after.

Safety first: Disconnect power at the breaker before removing any access panels. Refrigerant work must be performed by a licensed technician.

• Check airflow across the evaporator coil: Make sure the top grill and coil are free of leaves, plastic, and debris. Clean the coil gently with a hose from inside out.
• Verify fan operation: Restore power briefly and confirm the fan runs whenever the compressor is commanded on. If the fan is not running, shut power off and inspect the fan motor and capacitor.
• Inspect for obvious oil stains: Look around refrigerant joints, service valves, and the compressor base for oily residue, which can indicate a refrigerant leak.
• Reset the unit: After cleaning and verifying airflow, power the unit off for 5 minutes, then back on. If LP reappears, do not continue to run the unit.
• Call a professional: Low pressure faults often indicate low refrigerant or a restriction. A Heat Siphon–qualified technician should leak‑check, repair, evacuate, and recharge the system to factory specifications.