How to Prime a Well Pump

Priming a well pump is an essential task to ensure your water system operates efficiently and reliably. When a pump loses its prime, it can no longer draw water effectively, leading to interruptions in your water supply. By following the proper steps, you can restore the pump’s functionality and prevent potential damage to the system. This guide will walk you through the process of how to prime a well pump safely and effectively.

Why Priming a Well Pump is Necessary

Priming a well pump is crucial because it ensures the pump is filled with water, which is necessary for creating the suction needed to draw water from the well. Without priming, air can enter the pump and disrupt its ability to function, potentially leading to mechanical wear or damage over time. Properly priming the pump helps maintain consistent water flow and prevents issues such as overheating or dry running, which can shorten the pump’s lifespan. Regularly checking and priming the pump is essential for the overall efficiency and longevity of your water system.

Tools and Materials Needed

To successfully prime a pump, you will need a few essential tools and materials to ensure the process is done correctly and efficiently. These include:

• Clean Water: A sufficient amount of water is necessary to fill the pump and create the required suction.
• A Funnel: Useful for pouring water into the pump without spillage.
• Wrenches: Adjustable wrenches or specific-sized wrenches to open the priming plug or access other components of the pump.
• Bucket: To carry and hold water for the priming process.
• Rags or Towels: To clean any water spills or wipe components during the process.
• Lubricant (if needed): For maintaining seals and ensuring smooth operation of pump mechanisms.
• Instruction Manual: The specific manual for your pump model can guide you through the priming process effectively.

Having these tools and materials ready beforehand can streamline the priming procedure and reduce downtime for your water system.

10 Methods How to Prime a Well Pump

1. Shut Off Power to the Pump Before Starting

Before attempting to prime a well pump, always begin by turning off the electrical power supply. This is crucial for safety and ensures that the pump doesn’t run dry while air is still in the system. Running a dry pump can damage internal components such as seals and impellers. Locate the circuit breaker or switch that controls the pump and verify that no power is reaching the unit. This step creates a safe environment to work in and prevents accidental operation during the priming process.

2. Locate the Priming Plug on the Pump Housing

Next, find the priming plug on the top of the pump housing. This plug allows you to add water directly into the pump casing. In most jet or centrifugal pumps, the plug is a threaded fitting, often made of brass or plastic. Use an adjustable wrench or pliers to remove the plug. Keep a bucket or rag nearby to catch any residual water that may spill out. Identifying the correct plug is essential, as adding water through the wrong opening may not reach the impeller chamber.

3. Fill the Pump Housing with Clean Water

Using a funnel or a garden hose with a shutoff nozzle, slowly pour clean water into the priming port. Continue filling until the pump housing is completely full. This may take several gallons, depending on the size of the pump and the length of the suction pipe. The goal is to eliminate air pockets and fully submerge the internal components. If water drains quickly, it may indicate air leakage or an open valve further down the system. Ensure all suction lines are tight and sealed before continuing.

4. Open the Pressure Relief Valve or Faucet

To assist in the priming process, open a nearby faucet or the pressure relief valve on the system. This helps allow trapped air to escape from the system as water enters, making the priming more efficient. If your pump is connected to a pressure tank, opening a faucet also prevents air from being compressed in the tank, allowing for a smoother water draw when the pump begins to operate.

5. Inspect the Foot Valve or Check Valve

A common reason for lost prime is a faulty foot valve (located at the bottom of the well pipe) or a leaky check valve. These valves prevent water from flowing backward into the well once the pump is turned off. If priming fails repeatedly, inspect or replace these valves. A leaking foot valve will cause water to drain out of the suction line when the pump is off, requiring frequent re-priming. Replacing a worn-out check valve can solve this issue and help the system retain its prime.

6. Use a Self-Priming Pump or Manual Hand Pump

If your setup includes a self-priming jet pump or has a manual hand pump installed inline, you can use these features to draw water into the system more effectively. A manual pump can help pre-fill the suction line, particularly in shallow well systems. These pumps use suction to move water from the well into the main casing, allowing the electric pump to complete the cycle. This method is especially helpful when you have difficulty filling the pipe manually.

7. Seal the Priming Plug and Turn the Power Back On

Once the pump housing is filled and all air has been purged, carefully reinstall the priming plug, ensuring it is tightly sealed to prevent air from re-entering the system. With the plug secured, restore power to the pump. Watch and listen carefully: the pump should start and build pressure gradually. You may hear gurgling or bubbling as the last pockets of air exit through the open faucet or relief valve. If pressure builds and water flows steadily from the outlet, the pump has been successfully primed.

8. Repeat Priming Steps if Necessary

Sometimes the priming process must be repeated more than once, especially if the suction line is long or if air has infiltrated deeply into the piping. If water does not begin flowing after a few minutes, turn the power off again and refill the pump casing. Be patient and persistent; stubborn airlocks can take time to remove. If your system includes a horizontal or uphill suction line, air can collect in high spots and make the process slower.

9. Monitor the Pressure Gauge and System Behavior

Once the pump begins operating normally, keep an eye on the pressure gauge and system performance. A typical residential system should build pressure to around 40–60 PSI. If the pump short cycles or struggles to maintain pressure, there may still be air trapped or another mechanical issue like a clogged impeller or air leak. Consistent monitoring during the first hour of use after priming is critical to ensure the system is stable and efficient.

10. Install a Priming Tee or Priming Port for Future Use

For future convenience, consider installing a priming tee or permanent priming port on your pump system. These additions make the process easier and quicker, especially in areas prone to seasonal pump shutdowns, like cabins or vacation homes. A priming tee allows you to fill both the pump and suction line without removing any parts or plugs. Installing such a fitting during initial setup or maintenance can save time and effort during future priming operations.

Things to Consider When Installing a Priming Tee or Port

Location of Installation

Choose an easily accessible location for the priming tee or port. This ensures that future priming tasks can be performed with minimal effort and without the need to disassemble other components of the pump system.

Material Compatibility

Use materials that are resistant to corrosion and compatible with your pump system. This is especially important in systems handling water with high mineral content or other corrosive elements.

System Pressure Ratings

Ensure that the priming tee or port and its connections are capable of withstanding the pressure of the system. This helps prevent leaks or failures under operating conditions.

Sealing and Threading

Proper sealing and threading are crucial to prevent air leaks, which could disrupt the priming process. Use thread sealant or plumber’s tape where necessary to maintain a tight seal.

Future Maintenance

Plan for easy maintenance and inspections. Incorporate valves or caps on the priming port that can be securely closed to avoid accidental leaks during operation.

Conclusion

Priming a well pump may seem like a daunting task, especially for first-time homeowners or DIY plumbers, but with the right preparation and understanding, it becomes a manageable and essential skill. Whether you’re dealing with a jet pump, shallow well, or centrifugal system, following these ten comprehensive methods ensures a safe and effective return to service.

From verifying foot valves to filling the housing properly and testing for leaks, each step builds confidence in your system’s performance and reliability. Thanks for reading our blog post on how to prime a well pump! We hope you found it helpful and informative.