Pump display shows E05; motor will not start or runs erratically.

Safety first: Disconnect power at the breaker and wait several minutes for internal capacitors to discharge before opening any covers.

Steps to evaluate an internal drive fault:

• 1. Power cycle the pump: Turn the breaker OFF for at least 2–3 minutes, then turn it back ON. If E05 reappears immediately, the fault is likely persistent.
• 2. Inspect the drive enclosure: Check the control keypad and drive housing for cracks, water stains, or condensation. Any sign of water inside the electronics area indicates a failed seal.
• 3. Check for burn marks or odor: With the cover removed (if allowed by Pentair’s instructions), look for burnt components, darkened PCB areas, or a burnt smell. Do not touch the board components.
• 4. Verify proper bonding and grounding: Ensure the bonding lug is connected to the pool bonding grid and the equipment is properly grounded. Poor bonding can increase susceptibility to surges.

Internal drive faults are not field-repairable. If E05 persists after a power cycle and wiring checks, the recommended action is to replace the complete motor and drive assembly or the drive module per Pentair guidelines. Contact a Pentair-authorized service center for warranty evaluation if applicable.