Pentair IntelliFlo XF Priming Failure

The priming failure alarm is one of the most common alarms on the Pentair IntelliFlo XF. It indicates the pump could not establish sufficient water flow within the configured Max Priming Time. All control panel buttons are disabled until the alarm is acknowledged with the Reset button.

How the Priming Alarm Works

If the pump is not defined as primed within the Max Priming Time, it will stop and generate a Priming Alarm for 10 minutes, then attempt to prime again. If the pump cannot prime within five attempts, it will generate a permanent alarm that must be manually reset by pressing the Reset button on the control panel.

During priming, the pump speeds up to 1800 RPM and pauses for 3 seconds. If there is sufficient water flow in the pump basket, the pump exits priming mode and runs its commanded speed. If flow is insufficient, the pump increases to the Priming Speed and runs for the Priming Delay time (default 20 seconds). If still insufficient, the pump runs at the Priming Speed for the full Max Priming Time before triggering the alarm.

What Causes Priming Failure?

Air Leaks in the Suction Line

Air entering the suction side is the most common cause of priming failure. The manual directs you to check suction piping and valve glands on any suction gate valves, and to be sure the lid on the pump strainer pot is secure with the lid gasket in place.

• Loose or cracked pump strainer lid
• Worn or missing lid O-ring
• Loose union connections on suction piping
• Worn valve stem O-rings on suction gate valves

Insufficient Water

The manual states: be sure the suction lines, pump, strainer, and pump volute are full of water. Also check water level to be sure the skimmer is not drawing air.

• Pool water level below the skimmer opening
• Suction lines or pump volute not full of water
• Closed or partially closed suction valves

Clogged Components

Blockages restrict water flow and prevent the drive from detecting sufficient flow to confirm prime.

• Clogged pump strainer basket — clean the strainer pot
• Defective pump strainer gasket — replace the gasket
• Air pockets or leaks in suction line causing reduced capacity
• Clogged impeller — disassemble and clean debris from the impeller

Step-by-Step Troubleshooting

Step 1: Check Water Level

Verify the pool water level is high enough that the skimmer is not drawing air. Add water if needed before attempting a restart.

Step 2: Inspect the Pump Lid and Gasket

1. Turn off power to the pump at the circuit breaker
2. Remove the pump lid
3. Inspect the lid gasket for cracks, flat spots, or debris
4. Clean and re-seat the gasket; replace if damaged
5. Check the lid for cracks or warping
6. Reinstall and ensure a proper seal

Step 3: Fill the Pump with Water

1. Open the pump lid
2. Fill the strainer pot completely with water
3. Replace the lid and ensure it seals properly
4. Restore power and start the pump

Step 4: Check Suction Valves

Verify all suction-side valves are fully open. A partially closed valve restricts flow and can prevent successful priming.

Step 5: Inspect Suction Piping for Air Leaks

Check suction piping and valve glands on any suction gate valves. While the pump is running, look for air bubbles in the pump basket or water spraying from fittings.

Step 6: Clean the Strainer Basket and Impeller

Turn off power. Remove the strainer basket and clean it. If reduced capacity persists with a PRIMING FAILURE display, the impeller may be clogged. To clean the impeller:

1. Remove the six bolts holding the housing to the seal plate
2. Slide the motor and seal plate away from the volute
3. Clean debris from the impeller
4. If debris cannot be removed, remove the diffuser and O-ring, remove the reverse-thread impeller screw and O-ring, remove and clean the impeller, then reinstall in reverse order
5. Reinstall the motor, seal plate, and volute; tighten securely

Step 7: Reset the Alarm and Restart

Press the Reset button on the control panel to clear the alarm once the fault condition has been resolved. If a permanent alarm has been triggered (after five failed attempts), the Reset button must be pressed manually before the pump can attempt to prime again.

Adjusting Priming Settings

If the pump does not come out of priming mode, adjust the Priming Range to a higher setting (default is 5). If the pump exits priming mode too early with air still in the housing, adjust the Priming Range to a lower setting.

To access priming settings: press Menu, scroll to Priming, press Select.

Setting	Default	Range
Priming Enable/Disable	Enabled	Enabled / Disabled
Priming Speed (Set Speed)	3450 RPM	2350–3450 RPM
Max Priming Time	11 minutes	1–30 minutes
Priming Range	5	1–10
Priming Delay	20 seconds	1 second–10 minutes

The Max Priming Time (1–30 minutes) is the amount of time the pump will try to prime before it gives a priming error. If the pump continues to show a priming error, increasing the Priming Delay time may correct the issue by allowing the system more time to stabilize before the pump transitions to its commanded speed.