Unit displays LP and will not heat; compressor may attempt to start and then shut down.

Safety first: Disconnect power before removing any panels. Refrigerant work must be done by an EPA‑certified technician.

• Check ambient conditions: Confirm the outside air temperature is within AquaCal's specified operating range. Many heat pumps will show LP if the air is too cold.
• Inspect airflow: Ensure the fan is running and the evaporator coil is not iced over or blocked. Clear debris and rinse the coil with low‑pressure water if dirty.
• Look for obvious oil stains: With power off, inspect refrigerant line connections and coil areas for oily residue, which can indicate a refrigerant leak.
• Reset the unit: Restore power and attempt to restart. If LP returns quickly, shut the unit down to prevent compressor damage.
• Call a technician: A licensed AquaCal service technician should check the low‑pressure switch, verify refrigerant charge, and locate/repair any leaks.