Pool heat pump will not start; display shows E01 and compressor does not engage.

Safety first: Turn off power at the pool heater disconnect and the main breaker before opening any panels. Do not work on the refrigerant circuit yourself; this requires a licensed HVAC technician.

• Check water flow: Ensure all pool valves to and from the SPRSUN heat pump are fully open. Clean or backwash the pool filter and empty the pump baskets. Low water flow can cause high pressure.
• Inspect airflow: Ensure there is at least 24–36 inches of clearance around the unit and above the fan. Remove leaves, plastic bags, or debris from the top grille and side panels so that the condenser coil can reject heat.
• Clean condenser coil: With power off, gently hose off the outside coil fins from the inside out, if accessible. Do not use high pressure, as this can bend the fins.
• Reset the unit: After restoring proper water flow and airflow, restore power and use the control panel to clear the alarm (or power-cycle the unit for 5 minutes). If E01 returns quickly, the high pressure switch or refrigerant charge may be faulty.
• When to call a technician: If the unit repeatedly trips E01 with good water flow and clean coils, contact a qualified heat pump technician to test the high pressure switch, check operating pressures, and correct the refrigerant charge.