Why Is Your Well Pump Running but Not Building Pressure

Updated on:
January 5, 2024

If you’ve ever found your well pump chugging away tirelessly yet failing to deliver the much-needed water pressure, you’re not alone. This head-scratcher can leave you puzzled and frustrated, especially when all you crave is a steady flow of water. 

But fear not, for I’m here to shed some light on this common conundrum and help you understand the possible reasons behind this hiccup in your water supply. 

In this article, I’ll dive into the mysteries of why your well pump seems to be working overtime without building up that essential pressure, and more importantly, we’ll explore potential solutions to get that water flowing smoothly once again. 

Read on to find out more!

Types of Well Pumps

To get the ball rolling, it’s important to know that there are two main types of water well pump: submersible pumps and jet pumps. Each works differently to pump water from a well, and there are various reasons why they might experience low pressure issues. 

Submersible pump

Submersible pumps are installed inside the well, submerged in water. They are typically more efficient and have a longer lifespan than jet pumps. Submersible pumps work on the principle of pushing water to the surface using a combination of impellers and a sealed motor. 

Jet pumps

There are two main types of jet pumps, shallow-well jet pumps and deep-well jet pumps. 

  • A shallow-well jet pump is designed for wells with a depth of up to 25 feet. It uses a single pipe to draw water and create a vacuum that lifts the water to the surface. 
  • A deep-well jet pump is built for deeper wells. This pump uses a two-pipe system. The first pipe draws water from the well and into a jet assembly, which creates a vacuum. The second pipe pushes water to the surface.

Common Causes of Low Pressure in Submersible Pumps

Some causes of low water pressure in submersible pumps include the following:

1. Low water levels

One of the most common causes of low pressure in submersible pumps is low water levels in the well

The pump’s intake, which is responsible for drawing water into the system, is located at the bottom. When the water level in the well drops below the pump’s intake, there is simply not enough water available for the pump to operate efficiently, if at all. As a result, the pump ends up running dry, and no water can be delivered to the surface.

When a submersible pump operates without sufficient water around its intake, several issues arise. 

First, the pump loses its prime, meaning it can no longer create the necessary pressure difference to push water upward. This leads to the impeller spinning in the air, causing excess friction and heat, which can damage the pump’s internal components. 

Additionally, the lack of water as a cooling agent can cause the pump’s motor to overheat, potentially leading to motor failure.

To prevent the low pressure issue caused by low water levels, it’s crucial to monitor the water level in your well regularly, especially during times of drought or heavy water usage. If the water level gets too low, refrain from using the pump until the water source has had a chance to replenish. 

A low water level sensor or a well level indicator can provide you with real-time information about the water level in the well and allow you to take timely action to avoid pump damage.

2. Damaged or malfunctioning pressure tank 

The pressure tank plays a crucial role in maintaining consistent water pressure in the system. It acts as a reservoir, storing water and pressurizing it so that when a faucet is opened, water flows out at a steady rate. 

Pressure tank damage

If the pressure tank develops a problem, such as a ruptured diaphragm or a failed air charge, it may lose its ability to maintain pressure. As a result, the pressure in the water system drops significantly. If the pressure drops below a certain threshold, the submersible pump may lose its prime.

A malfunctioning water pressure tank can cause rapid and frequent pump cycling. When the pressure tank loses its ability to maintain a steady pressure, the pump may turn on and off rapidly as it attempts to maintain the desired water pressure. 

Frequent pump cycling can lead to excessive wear and tear on the submersible pump, potentially leading to pump failure and a subsequent lack of water flow.

Waterlogged pressure tank

Over time, pressure tanks may become waterlogged, meaning that too much water is present in the tank, leaving insufficient space for air. A waterlogged pressure tank can cause the pump to short cycle for insufficient air to compress and maintain proper pressure. This can lead to the pump running without effectively drawing water from the well.

Malfunctioning air control valve

Also, pressure tanks are equipped with an air volume control device that ensures the proper air-to-water ratio in the tank. If this device malfunctions, the pressure tank may not have enough air pressure to maintain proper water levels. This can cause the pump to struggle to draw water, leading to reduced or no water flow.

To address pressure tank issues, it’s essential to conduct regular maintenance and inspections. If you experience a low pressure problem with your submersible pump, it’s a good idea to check the pressure tank for any signs of damage, waterlogging, or improper air charge. If you suspect pressure tank issues, it’s best to consult a professional well pump technician or plumber to assess and repair the problem properly.

3. Pressure switch issues

The pressure switch is responsible for signaling the submersible pump to start when the water pressure drops below a certain pre-set level (cut-in pressure). If the pressure switch fails to detect the drop in pressure or is stuck in the “off” position, it won’t activate the pump even when water is needed. As a result, the submersible pump won’t engage, and no water will be pumped from the well. 

Alternatively, if the pressure switch fails to detect the increase in pressure or is stuck in the “on” position, it won’t stop the pump when the desired pressure is reached. The pump will continue running, potentially leading to over-pressurization of the system and causing no water flow due to excessive pressure.

Pressure switches have adjustable cut-in and cut-out pressure settings. If the pressure switch is misadjusted, it might prevent the pump from starting or stopping at the appropriate pressure levels, resulting in either no water flow or constant running of the pump. 

They also rely on electrical connections to function correctly. Loose or damaged electrical connections can interfere with the pressure switch’s ability to control the pump, leading to a low pressure situation. This often happens when the pressure switch tubing is clogged.

It’s crucial to perform regular inspections and maintenance on the pressure switch and the overall well water system. 

If you suspect pressure switch problems and experience a low pressure issue with your submersible pump, it’s best to consult a professional well pump technician or plumber. They can test and diagnose the issue, make necessary adjustments, and replace with a new pressure switch if required.

4. Broken water line

The primary function of a submersible pump is to draw water from the well and push it through the water lines to the surface. If there is a break or leak in the water line between the pump and the water source, water will not reach the pump properly, and the pump will lose its prime. As a result, the pump can’t maintain the pressure required to draw water effectively. 

When there is a break in the water line, air can get into the system and become trapped, a phenomenon known as an airlock. These airlocks can prevent the submersible pump from functioning correctly as it struggles to draw water due to the presence of air in the lines.

To avoid this scenario, it’s essential to locate and repair the break as soon as possible. This task may require professional assistance, especially if the water line is buried underground. Regular inspections and maintenance of the water lines can also help prevent such issues and ensure a continuous water supply from your well.

5. Clogged intake screen

The intake screen, also known as the pump screen or pump filter, is positioned around the intake openings of the submersible pump. Its purpose is to act as a barrier, preventing sand, sediment, debris, and other large particles from entering the pump. This is crucial to protecting the pump’s impellers and internal components from damage and ensuring efficient water flow.

Over time, as the debris accumulates, it creates a physical barrier that prevents water from entering the pump. This reduces the water flow around the impellers, causing the pump to struggle to draw water from the well. Also, with a clogged water filter, the pump may draw in air instead of water, leading to a loss of prime and the inability to lift water to the surface.

  • As the pump struggles to work against the obstruction, it may overheat, potentially damaging the electric motor and other internal components. Cleaning the intake screen periodically can help prevent debris buildup and ensure smooth water flow. If the screen is severely clogged or damaged, it may need to be replaced.

Common Causes of Low Pressure in Jet Pumps

Below is a list of known causes of low or no pressure issues in well water jet pumps:

1. Airlock

Airlocks occur when air gets trapped in the pump or water lines, obstructing the flow of water and causing the pump to lose its prime. When an airlock occurs in a shallow-well jet pump, whether in the suction pipe or the pump itself, the vacuum is disrupted, and the pump is unable to draw water. As a result, the pump only pumps air.

In deep-well jet pumps, airlocks can occur in either the suction pipe or the drop pipe that extends down into the well. When air gets trapped in these pipes, it prevents water from reaching the jet assembly and disrupts the vacuum. The pump then fails to draw water.

To address airlock problems in jet pumps, the air must be removed from the system to restore water flow. Priming the pump properly by filling it and the pipes with water is often the first step. 

Additionally, checking and repairing the foot valve and check valve can help prevent air from entering the system. If the airlock is persistent or severe, it’s best to consult a professional well pump technician or plumber to diagnose and resolve the issue effectively. 

Proper maintenance and regular inspections of the jet pump system can help prevent airlock problems and ensure a continuous water supply from your well.

2. Failed foot valve 

In jet pump systems, the foot valve is typically located at the end of the drop pipe, which extends down into the well. 

It is equipped with a one-way check valve that allows water to flow upward into the drop pipe and pump while preventing it from flowing back down into the well when the pump is not running. The foot valve plays a crucial role in maintaining the prime of the pump, ensuring that water is readily available for suction.

Over time, the foot valve may experience wear and tear, corrosion, or damage, leading to failure. When the foot valve fails, it can no longer create a proper seal, and water may leak back into the well when the pump is turned off. As a result, the pump loses its prime, and air may enter the pump and water lines when the pump is running, causing airlocks.

To sort out foot valve problems and the resulting low pressure issue in jet pumps, the failed foot valve must be replaced. It’s essential to hire a professional well pump technician or plumber to inspect the foot valve and diagnose the problem correctly. They can then replace the faulty foot valve and ensure that the new valve is properly installed and functioning.

3. Clogged impeller or nozzle

In a jet pump, the impeller is located within the pump housing and is responsible for creating a vacuum by spinning rapidly. The spinning impeller draws water into the pump through the intake and into the venturi section, where the nozzle is located. 

The nozzle is a narrow passage that accelerates the water flow, creating a jet that propels the water to the surface. This process relies on a continuous flow of water through the impeller and nozzle to maintain the vacuum required for water suction.

Over time, jet pumps can accumulate debris, such as sand, silt, algae, or other particles, which can clog the impeller or nozzle. 

When either component becomes clogged, water flow is restricted, reducing the efficiency of the pump and, in some cases, causing the pump to lose its prime. The clogged impeller or nozzle disrupts the creation of the necessary vacuum, leading to the pump’s inability to draw water effectively from the well.

To address clogging issues, it’s essential to conduct regular maintenance and inspections. Cleaning the impeller and nozzle periodically can help prevent debris buildup and ensure smooth water flow. 

In cases where clogging is severe or persistent, a professional well pump technician or plumber should be consulted. They can inspect and clean the impeller and nozzle or, if necessary, replace any damaged components.

4. Pump motor failure 

The pump’s electric motor is responsible for driving the impeller and creating the necessary air pressure difference for water suction. 

If the pump motor experiences issues, such as a burned-out motor or mechanical failure, it may not spin the impeller effectively. As a result, the pump loses its ability to create the required vacuum, leading to a low pressure scenario. Electrical problems, such as loose connections or voltage irregularities, can also impact the pump motor’s performance. 

When pump motors are continuously running without drawing water, they may overheat and activate a thermal overload protection feature. The thermal overload protection shuts off the motor to prevent damage from excessive heat. While this feature protects the motor, it can also result in a low pressure issue as the pump is temporarily disabled until it cools down.

To avoid this, conduct regular maintenance and inspections. Ensuring the pump motor is in good working condition and checking the electrical connections can help prevent this issue. If you aren’t well versed with electrical DIY projects, I recommend hiring a certified technician to fix the issue.

5. Control box issues

Some jet pumps use a control box to manage the pump’s operation and motor speed. The pump control box contains electrical components that regulate its performance. If the control box malfunctions or has faulty components, it can lead to erratic pump behavior or the pump not running at all.

The control box houses the pressure switch, which controls the pump’s operation based on water pressure levels. When the pressure drops below a certain pre-set level (cut-in pressure), the pressure switch signals the pump to start. 

If the pressure switch malfunctions or gets stuck in the “off” position, it won’t activate the pump even when water is needed. This results in the pump not drawing water.

If control box problems are suspected, seek professional assistance from a well pump technician or plumber. They can diagnose and repair the specific issues to restore the pump’s proper operation and ensure a continuous water supply from your well.

6. Faulty pressure gauge

The pressure gauge in a jet pump system monitors and displays the water pressure within the system. It allows homeowners and technicians to observe the pressure levels and ensure that the pump is running within the desired range. A defective pressure gauge may display inaccurate pressure readings or may not show any pressure at all. 

If the pressure gauge is faulty, it might indicate that there is enough pressure for the pump to operate when, in reality, the pressure is insufficient. As a result, the pump may not have enough pressure to pump water from the well. 

A pressure gauge defect can lead to misdiagnosing pump issues, as it may not accurately indicate the underlying problems affecting the pump’s performance.

If you suspect a pressure gauge problem or experience a low pressure situation with your jet pump, consult a professional well pump technician or plumber. They can test and diagnose the pressure gauge, and other components to identify any issues accurately and address them promptly.

7. Water filtration system

Water filtration systems use filters to trap sediment, debris, and contaminants. Over time, these filters can become clogged and restrict water flow. 

If the filters are not replaced or cleaned regularly, they may prevent water from entering the jet pump at the required rate. Reduced water flow means the pump won’t receive enough water to create the necessary pressure for operation.

Some water filtration systems, especially those with low flow rates, may not provide an adequate water supply to meet the demands of the jet pump. If the filtration system does not deliver sufficient water, the jet pump may struggle to draw water from the well, leading to low or no water pressure.

Water filtration systems may include backflow prevention devices to prevent water from flowing backward into the system. While these devices are essential for preventing contamination, they can cause a reduction in water pressure by restricting water flow into the jet pump. 

The filtration process itself can create pressure losses due to the flow resistance in the filters, pipes, and other components. If the filtration system is not properly designed or installed, it may lead to significant pressure drops, affecting the overall water pressure delivered to the jet pump.

To mitigate the no-pressure issue caused by a water filtration system, proper installation, regular maintenance, and correct sizing of the filtration system are essential. Ensuring the filters are cleaned or replaced as recommended by the manufacturer will prevent clogging and maintain a healthy water flow rate. 

Alternatively, if you encounter a no-pressure problem with your jet pump after installing a water filtration system, consult a professional plumber or well pump technician.


Now that we’ve explored the ins and outs of why your well pump might be running without building pressure, you’re armed with valuable knowledge to tackle this issue head-on. 

Remember, when facing such situations, stay calm and methodically troubleshoot the potential culprits. Whether it’s a low water level, a faulty water pressure tank, air in the system, pump problems, or clogged pipes, there’s no need to panic. Engage the help of a skilled well pump technician if needed, and they’ll have you back in the flow of things in no time.

Also, by maintaining your well system regularly and being proactive in addressing any problems that arise, you can ensure a steady and efficient water flow for your household needs.

If you’re looking to delve deeper into well water pumps, here are extra resources offering comprehensive insights.

Notify of

Inline Feedbacks
View all comments