How to Prime a Deep Well Pump in 6 Steps

Before you start the priming process, make sure all of your plumbing system’s taps are shut off. Otherwise, the water you add to the pump casing will flow out of the system.

Water and electricity don’t mix well, so start the priming process by turning off the well pump and disconnecting it from power sources. Either unplug the pump from its outlet or turn it off from the breaker circuit to remove the risk of electrocution. 

This is also a good time to inspect your pump and its components for any damage, especially if you’re having a water line issue or have left the pump dormant over winter months. Make sure all nuts and bolts are in place, retighten drain plugs, and manually test valves. If you can’t tell your nuts from your bolts or you’re hesitant to move to the next step, call a pro to quickly handle this job for you.

To get access to the pump system, remove the prime plug. Look for a square or hexagonal-shaped plug located at the top of the pump, and unplug it to expose a hole in the top of the pump.

To avoid pressure building up in your pipes during priming, open your pump’s water pressure release valves. For most water pressure tanks, you can simply use the associated lever to lift the valve up until the attached stem rises, causing water to flow from the pipe and into the bottom of the water tank.

With the pump system accessible, the next step is to fill the pump casing with water. It’s important to note that the water you use for this step needs to be at least of the same quality as the water in the well. If you use the well for drinking or potable water, for example, then the water source you use needs to also be of potable quality.

In most cases, a hose that’s connected to a clean water supply works well for priming. Ensure that this hose is lead-free—most hoses include a manufacturer’s label that lists materials and designates them as drinking safe or not. If you don’t have a hose handy, a large and clean bucket or bottle should also get the job done. The actual amount of water you need varies depending on the size of your well pump and the depth of your well, but a few gallons should do.

Whether you have a bucket or a hose, fill the casing with water until it’s full. Watch for the casing to start to overflow from the prime plug hole and the release valves to know when it’s full.

With the pump casing full, you can replace the prime plug and reconnect the pump to its power source. 

Turn the pump on and let it run through a few cycles. You may hear the pump loudly drawing water from the well at first, but it should settle into a regular start-and-stop cycle within a few minutes. Close any release valves once water runs through them.

If the water pump doesn’t resume a normal cycle or your water pressure is inadequate, you may need to repeat this process.