A deep well pump that won't start can bring your entire water system to a halt. Whether you're dealing with a newly installed pump or one that's lost its prime after sitting idle, knowing how to properly prime your deep well pump is an essential skill for any homeowner with a private water supply.

Priming is the process of filling your pump and pipes with water to create the necessary suction for pumping. Without proper priming, your pump will run dry, potentially causing damage to the motor and internal components. The good news? With the right approach and a bit of patience, you can get your deep well pump working again.

This guide walks you through everything you need to know about priming a deep well pump, from understanding why it's necessary to troubleshooting common issues.

Why Deep Well Pumps Lose Their Prime

Before we jump into the priming process, it helps to understand why pumps lose their prime in the first place.

Air leaks are the most common culprit. Even small cracks in pipes, loose fittings, or worn seals can allow air to enter the system. Once air gets in, it displaces the water your pump needs to function.

Extended periods of inactivity can also cause problems. If your pump hasn't been used for weeks or months, water may have drained back down the well, leaving the pump chamber empty.

Low water levels during dry seasons can expose the pump intake to air rather than water. Finally, new installations always require priming since the system starts completely dry.

What You'll Need

Gather these supplies before you begin:

· A source of clean water (5-gallon bucket or garden hose)

· Screwdriver or wrench (depending on your pump model)

· Funnel (optional but helpful)

· Teflon tape (for resealing connections)

· Towels or rags (to clean up spills)

Make sure you know where your pump's pressure switch and circuit breaker are located. You'll need to access both during the priming process.

Step-by-Step: Priming Your Deep Well Pump

Step 1: Turn Off the Power

Safety comes first. Locate your pump's circuit breaker and switch it off. Double-check that the pump is completely powered down before proceeding. Working with water and electricity requires caution.

Step 2: Locate the Priming Port

Most deep well pumps have a priming plug or valve on top of the pump housing. This is typically a ½-inch or ¾-inch threaded plug. Consult your pump's manual if you're having trouble locating it. Some models may have a designated priming tee installed in the discharge line instead.

Step 3: Remove the Priming Plug

Use a wrench to carefully loosen and remove the priming plug. Have a towel ready—some water may spill out if there's still pressure in the system. Set the plug aside in a safe place where you won't lose it.

Step 4: Fill the Pump with Water

Here's where the actual priming happens. Using your bucket or hose, slowly pour clean water into the priming port. You want to fill the pump casing completely until water begins to overflow from the opening.

Take your time with this step. Rushing can trap air bubbles inside the pump chamber, which defeats the purpose of priming. If you're using a bucket, you may need to refill it several times depending on your pump's capacity.

Step 5: Replace the Priming Plug

Once water is overflowing from the port, quickly replace the priming plug. Wrap the threads with Teflon tape before screwing it back in to ensure a tight seal. Tighten the plug securely, but don't overtighten—you could crack the housing.

Step 6: Restore Power and Test

Turn the circuit breaker back on. Your pump should begin running automatically as it tries to build pressure. Listen carefully. You should hear the motor running smoothly without unusual grinding or whining sounds.

Check your pressure gauge. The pressure should begin climbing toward the cut-off point (usually 40-60 PSI for residential systems). This might take a few minutes as the pump pushes water through the entire system.

Step 7: Check for Leaks

While the pump is running, inspect all connections, fittings, and the priming plug for leaks. A small amount of moisture is normal, but steady drips indicate a problem that needs attention.

Open a faucet inside your home to release any trapped air from the system. You may notice sputtering or discolored water at first. Let it run until the flow becomes steady and clear.

Troubleshooting: When Priming Doesn't Work

Sometimes priming isn't as straightforward as following the steps above. Here are solutions to common problems:

The pump runs but won't build pressure. This usually means air is still in the system. Repeat the priming process, making absolutely sure you've filled the pump completely. You may need to prime multiple times to eliminate all air pockets.

Water flows back down the well. Your foot valve at the bottom of the drop pipe may be faulty or clogged. This valve is supposed to prevent water from draining back into the well. If it's not sealing properly, you'll have trouble maintaining prime. Replacing a foot valve requires pulling the pump, which typically requires professional help.

The pump cycles on and off rapidly. Check your pressure tank. A waterlogged pressure tank or one with incorrect air pressure will cause short cycling. Test the air pressure in the tank (it should be 2 PSI below the cut-in pressure setting) and adjust if needed.

You hear the motor but no water flows. The impeller might be jammed with debris. Turn off the power and check for obstructions. If the problem persists, the pump itself may need repair or replacement.

Preventing Future Priming Issues

Once you've successfully primed your pump, take steps to prevent losing prime again:

Inspect your system regularly for leaks, especially at joints and connections above the well casing. Even minor drips can eventually lead to priming problems.

Ensure your foot valve is functioning correctly. If your pump frequently loses prime, consider having a professional check or replace the foot valve.

Maintain proper water levels. If your well is prone to running low during dry periods, you may need to adjust your pump depth or reduce water usage.

Install a check valve near the pump if your system doesn't already have one. This provides additional protection against backflow.

When to Call a Professional

While priming a deep well pump is generally a DIY-friendly task, some situations require expert help:

· You've primed the pump multiple times but it still won't hold prime

· You suspect damage to the drop pipe or pump components

· The pump makes unusual noises even after successful priming

· You're uncomfortable working with your home's water or electrical systems

· The pump is located in a difficult-to-access area

A licensed well pump technician has specialized equipment to diagnose and fix problems that aren't apparent from the surface.

Keep Your Water Flowing

Priming a deep well pump doesn't have to be complicated. With basic tools and a methodical approach, most homeowners can handle this task and restore their water supply without professional help.

Remember that prevention is easier than repair. Regular maintenance and quick attention to small issues will keep your pump running smoothly for years. Check your system periodically, especially before and after periods of non-use, to catch potential problems early.

If you find yourself repeatedly priming your pump or facing issues beyond basic troubleshooting, don't hesitate to contact a well pump specialist. A small investment in professional service can prevent major repairs down the road and ensure your household always has reliable access to water.

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