If you rely on a well for your water, it’s crucial to equip it with the right pump to keep your water flowing during peak usage hours. In this well pump guide, we’ll familiarize you with how a well pump works, the different types available and how to pick the best pump for your needs.
What Is a Well Pump?
In urban and suburban areas, most people have virtually constant access to potable, clean water. However, in more rural areas, millions of homes rely on wells for their water supply. A well pump is an electromechanical piece of equipment that gets installed after drilling or digging a well. Its purpose is to pump the water from your well into your house. An electric motor drives an impeller or centrifugal pump, which pushes water from your well through a jet or pipe.
They come in a wide range of sizes, and the best size for your home depends on three primary factors:
- Your property’s size
- How much water your household uses
- How many plumbing fixtures you have in your home
We’ll provide more detailed information on choosing the right pump size later on in the guide.
How Does a Well Pump Work?
The well pump pushes the water from your well into a storage tank, which will store it until you need it. When the motor is in operation, it will draw water into the pump, which then pushes it to the surface into a pressure tank.
Pumping water into this pressure tank will cause the tank’s air pressure to increase until it reaches a specific preset level, ranging from 40 to 60 psi. When you turn a faucet on in your house, the force of the lessening air pressure in the tank pushes water through your plumbing. Once the air pressure drops down to around 40 psi, this will turn the pump back on again, and the pump will immediately start to drive more water into the storage tank.
Types of Well Pumps
In many regions of the United States, the water table is just a few feet below the ground’s surface, and accessing it is easy — or at least easier than in areas with a lower water table.
You’ll have to dig further down to obtain the same result in areas with lower water tables, or regions that lack a consistent supply of drinkable water close to the surface. Because deeper wells require moving water over a longer distance, they need a different strategy.
What does a well pump look like? They come in various shapes and sizes. In this section, we’ll go over the most common types of well pumps and the situations where each pump is most suitable.
1. Centrifugal Pump
A centrifugal pump rotates an internal fan to create suction. Unlike other well pumps, centrifugal pumps sit in a mechanical housing next to the well instead of inside it, making maintenance less of a hassle.
One potential downside of centrifugal pumps is that their suction is not powerful enough for use in deep wells. Centrifugal pumps are only a viable option if your well is shallower than 25 feet. The centrifugal well pump tends to be the most affordable type.
2. Submersible Pump
The submersible pump is possibly the most prevalent type, in part due to the flexibility it offers. These pumps are practical for virtually any well, no matter how shallow or deep it is.
As their name suggests, submersible pumps are underwater, deep inside the well. These pumps are watertight, last a long time and rarely need repairs. However, repairs involve pulling the pump out of the well and up to the surface. A trained well pump repair technician can complete this task, but the labor involved will usually increase repair costs.
Some characteristics of submersible pumps include:
- They won’t function unless they’re entirely underwater.
- The motor powers impellers that push water up the pipe.
- Turning on the pressure switch causes the impellers to spin, which will push water up into a tank located on the surface.
3. Jet Pump
These sophisticated pumps provide the most power and can deliver more water faster than other types of pumps. Similar to their submersible counterparts, jet pumps work in wells at all depths.
The jet pump’s installation will depend on whether it’s “single-drop” or “double-drop.” Single-drop models, which are most suitable for shallow wells, are inside, either in your house or in an outbuilding. Double-drop models, which are most suitable for deep wells, require a split installation. Though the jet assembly is in the well, the motor must stay above ground.
While the upfront costs for submersible pumps are often higher, their generally lower maintenance costs make them a cheaper long-term investment.
Some defining characteristics of jet pumps are:
- The jet pump process relies on water to function.
- They create pressure via impellers.
- The impellers move water, also called drive water, through a small orifice mounted in the housing located in front of the impeller. Doing so increases the water’s speed.
- When the water leaves the jet, a vacuum will suck more water from the well. This water will combine with the drive water and discharge into your house at high pressures.
How to Choose a Well Pump
When choosing the right pump for your well, the single most crucial factor is your well’s depth — that is, how far the water must travel to get to the surface of the ground.
- If your well is less than 25 feet deep, you should use a shallow well jet pump.
- If the depth of your well is between 25 and 110 feet, you should use a deep well jet pump.
- If the depth of your well is between 110 and 400 feet, use a four-inch submersible pump. Remember, you can also use a submersible pump for wells as shallow as 25 feet.
To determine your well’s depth, look at the report provided by your well driller. If no such report exists, you can also determine it yourself. Find a long piece of string, attach a fishing bobber to one end, then lower the bobber down until you feel it floating. Mark the string once you remove the slack.
The Best Pump for Shallow Wells
If you have a shallow well, we recommend the single-drop jet pump.
These pumps come with one-way check valves, which serve to keep the pumps primed. The single-drop jet pump is aboveground and draws water up through one inlet pipe. Due to the relative simplicity of their mechanics, they generally don’t require as much maintenance as most other types.
A jet pump, the most popular option for a shallow well, sits over the well and draws up water via suction. The distance it can suck up the water depends on the air pressure. While air pressure changes with elevation, jet pumps generally are not ideal for wells more than 25 feet deep.
A jet pump generates pressure via its impeller, which pushes the drive water through a small orifice or a jet inside housing located in front of the impeller. The jet’s constriction increases the moving water’s speed.
As the water exits the jet, a vacuum will then suck more water out of your well. When this extra water comes together with the drive water, it will discharge into your house at high pressure.
Keep in mind that a shallow well jet pump’s process of drawing water also relies on water.
The Best Pump for Deep Wells up to 110 Feet
If you have a deep well, we recommend the double-drop jet-pump system.
Deep-well jet pumps are also above the ground, but they draw water by using two pipes. One of these pipes draws water out of the well, while the other pushes the water up. A deep well jet pump sucks up water from depths as great as 110 feet, and a foot valve is necessary for priming the pipe. Some models come with a tailpipe, which prevents users from pumping the well dry.
A deep well jet pump can draw water from further down than 25 feet if the jet is separate from the impeller’s housing and also in the water.
The impeller is responsible for driving water into the body of the jet, whereas the jet delivers the water back to your pump. A deep well jet pump uses suction at the jet for bringing water into the system. It also uses pressure to lift up water in the well and deliver it into the house.
A jet pump in a deep well will come with a 25-foot-long tailpipe attached to the jet’s housing on the intake side to prevent overpumping. When the water level dips below the jet’s housing, the tailpipe will ensure nobody can pump the well dry. The higher the jet sits above the level of the water, the more efficiently it will pump.
Just like with a shallow-well system, a deep-well system also requires priming with water. At the well’s bottom is a foot valve, which will prevent water drainage from the pipes.
The Best Pump for Deep Wells up to 400 Feet
If your well is deeper than 110 feet but not exceeding 400 feet, we recommend using a submersible pump.
Deep-well submersible pumps use pressure tanks to suction water via one pipe that connects the inside well to your house. These pumps can take in water from depths as low as 400 feet below ground, but one potential downside is that repairs require removal from the well casing.
While a jet pump can work with wells several hundred feet deep, they are generally not as effective for deeper wells as submersible pumps. As you move the pump further down your well, the pump will no longer lift the water — instead, it will push it upward. However, keep in mind that submersible pumps don’t work if not entirely submerged in liquid.
A submersible pump has a cylindrical shape, and the bottom half consists of a sealed pump motor that attaches to an aboveground power source. The motor powers impellers, which in turn drive the water upward. Turning on the pressure switch causes impellers to spin, thereby sucking water into the pump. The water gets pushed through the body of the pump, then into a storage tank on the ground’s surface.
Unlike aboveground well pumps, which are vulnerable to mechanical failure, submersible pumps tend to have fewer problems. Because submersible pumps are underwater, they don’t lose prime, an issue commonly experienced by aboveground pumps.
Cavitation, an occurrence when gas or air makes its way into a pump’s mechanical parts, is generally not an issue for a submersible pump because the pump sits far below the water’s surface and can always access water.
Even though a submersible pump can deliver water more efficiently than a jet pump with a similarly sized motor, any motor issues could require removing the entire unit from the well casing. Luckily, a submersible pump tends to be highly reliable and can operate at peak performance for as long as 25 years before needing maintenance.
How to Size a Well Pump
In addition to choosing the best pump for your well, you will also have to determine the size you need. Pump ratings are in terms of gallons per minute, and an average home with three or four bedrooms needs 8 to 12 GPM. When figuring out how much water your home needs, add one gallon per minute for each of your home’s water fixtures, such as dishwashers, clothes washers, refrigerators, faucets and showers.
While your pump needs to be sufficiently large to meet your home’s needs, an oversized unit will lead to reduced performance and energy inefficiencies. If you need to replace your pump, pick one with identical horsepower. However, note that you may need extra horsepower if you plan to add new family members or appliances. Pumps that must transport water over longer distances will require more horsepower.
If you’re going to replace your pump, check your pump’s identification plate to find its horsepower. Remember that a submersible pump might need either two or three wires, so you must find out the number of wires the new pump will require.
Contact Us About Our Well Pump Repairs
If your well pump needs speedy and reliable repairs, reach out to David LeRoy Plumbing. We’re available 24/7 to provide emergency fixes and answer any questions you might have.