How to Prime a Water Well Pump (Step by Step)

Priming a well pump means refilling the pump housing with water so it can push water instead of pulling air. It only applies to a shallow well jet pump that sits above ground. A submersible pump on a drilled well works underwater and has no priming plug to fill, so if your water stopped after a storm or a repair and you have a submersible system, priming is not the fix and opening the wellhead yourself is not a safe DIY step. Check which pump you have before you touch anything, then follow the steps below.

Does Your Pump Actually Need Priming?

Only a shallow well jet pump needs a manual prime, and you can usually tell which one you have by where the pump sits. A jet pump sits above ground, often in a basement, a utility closet, or a small pump house, and it pulls water up through a suction pipe using vacuum pressure. That vacuum is exactly what breaks when air gets into the line, which is why the pump needs a fresh water charge poured back into its housing before it can push water again. A submersible pump sits down inside the well casing itself, sometimes hundreds of feet underwater, and it pushes water up from below instead of pulling it. Because it is already submerged, it never loses its water charge the way a jet pump does, and there is no housing at the surface to refill. If your well was drilled, which describes most private wells across the Midlands and Upstate, you almost certainly have a submersible pump. If you are not sure, a wellhead with a wide visible casing pipe and no pump housing nearby is a strong sign of a submersible system.

What You Need Before You Start

Gather a clean bucket or pitcher of water, a garden hose if your model uses one for priming, a wrench that fits the priming plug, and the owner's manual for your specific pump if you still have it. Confirm the breaker for the pump is labeled correctly before you rely on it, since a mislabeled panel is one of the most common reasons someone thinks the power is off when it is not.

How to Prime a Shallow Well Jet Pump

1. Shut off power to the pump at the breaker and confirm it is off by trying the switch at the pump itself.
2. Find the priming plug on top of the pump housing and remove it with the wrench.
3. Look inside the housing, since a dry or only partly full housing confirms the pump lost its prime.
4. Pour clean water into the housing slowly until it is completely full, letting air bubble out as you go.
5. Replace the priming plug hand tight, open a faucet near the pump to release pressure, then restore power.
6. Watch the faucet, where water should run steady within a minute or two, first sputtering and then clearing.

If the housing refuses to hold water, or air keeps bubbling back in no matter how many times you refill it, stop. That points to a leak in the suction line or a foot valve that will not hold, and repeating the process will not fix either one.

What About a Submersible Pump on a Drilled Well?

If your well is drilled and your pump is submersible, do not attempt to prime it. There is no plug to open, and the actual problem, whether it is a failed check valve, a foot valve issue, or something wrong down in the casing, sits at the bottom of a well that may run hundreds of feet deep, wired into a live electrical drop. Working on that safely means pulling the pump correctly, which takes the right equipment and training, not a bucket of water and a wrench. Our guide to why a well pump loses prime walks through exactly what causes this on a submersible system, especially after a storm knocks the power out, and why the fix is a call rather than a weekend project. If you are not sure which type of pump you have, our well pump types guide helps you identify it before you decide what to try next.

How Do You Know If Priming Worked?

Steady, clear water at full pressure within a couple of minutes means it worked. A little sputtering right at the start is normal as the last of the air clears the line. What is not normal is water that starts strong and then fades, a pump that cycles on and off rapidly, or a faucet that never gets past a trickle. Any of those means the prime did not hold, and refilling the housing again will not change the outcome. That is usually a sign of a leak somewhere between the well and the pump, and it needs a technician to find rather than another round of pouring water in.

What If Priming Doesn't Fix It?

A jet pump that will not hold its prime after two or three honest attempts almost always has a mechanical problem: a cracked suction line, a foot valve stuck open, or a worn seal in the pump itself. None of those clear up with more water. At that point, Austin Drilling's pump services team can pressure-test the line, find the actual leak or failed part, and fix it instead of asking you to keep resetting a pump that was never going to hold. The same goes for any submersible system: if your water cut out suddenly and you are not sure why, our no water from a well guide covers the full range of causes so you know what you are dealing with before anyone touches the wellhead.

Frequently Asked Questions

How do I know if I need to prime my well pump?

If a jet pump runs but the faucet sputters, drips, or delivers nothing, and you can hear or see that the housing has lost its water charge, that is the sign you need to prime it. A submersible pump on a drilled well does not get primed this way at all.

Can I prime a submersible well pump myself?

No, because a submersible pump has no priming plug, since it already sits underwater inside the well casing. If a submersible system has no water, the cause is a valve or wiring issue that needs a technician, not a manual prime.

How much water does it take to prime a well pump?

Enough to completely fill the pump housing, usually a quart to a gallon depending on the pump size. Stop pouring once the housing is full and water no longer drops when you tilt it slightly.

What if I prime the pump and it still doesn't work?

Two or three failed attempts usually means a mechanical problem like a leaking suction line or a stuck foot valve, not something more priming will fix. That is the point to call for a proper diagnosis instead of repeating the process.

Is it safe to prime a well pump after a power outage?

For a shallow jet pump, yes, following the same steps above once power is confirmed off at the breaker. For a submersible system after an outage, treat it as a call, since the more likely cause is a valve issue down the well, not a lost prime.

How long should priming a well pump take?

The refill and restart itself takes a few minutes. If you are still fighting air in the line after two or three tries, stop rather than spending an hour on a fix that was never going to hold.

Priming a jet pump is a job most homeowners can handle carefully, but a submersible system on a drilled well is a different animal entirely, and guessing at it can cost you a pump motor or worse. If you have tried priming and it is not holding, or you are not sure which pump you even have, call Austin Drilling at West Columbia (803) 926-5402 or Newberry (803) 926-7080, Monday through Friday 7am to 6pm or Saturday by appointment, and we will figure out what is actually wrong before anyone touches the wellhead.