Davey pool pump controller shows E4 and the motor will not run.

Safety first: Switch off power at the breaker before opening the pump lid or unions.

Step-by-step checks:

• 1. Check water level: Ensure the pool water level is high enough to cover the skimmer opening by at least half.
• 2. Inspect pump lid O-ring: Remove the lid, clean the sealing surface, and inspect the O-ring for flat spots, cracks, or twists. Lubricate with silicone-based lubricant and reinstall. Replace the O-ring if damaged.
• 3. Tighten unions: Check the suction and discharge unions on the Davey pump wet end. Hand-tighten firmly; do not overtighten with tools as this can crack fittings.
• 4. Open all valves: Confirm that all suction valves (skimmer, main drain) and return valves are fully open.
• 5. Prime the pump: Fill the pump strainer housing completely with water, reinstall the lid securely, then restore power and start the pump. Watch through the lid to ensure the pump catches prime and runs with a solid column of water.
• 6. Clear the error: Use the controller's reset/start button to clear E4 once prime is established.

If E4 persists and the pump will not hold prime, there may be a hidden suction leak or damaged mechanical seal that requires a technician.