How to Replace a Well Pump: A Step-by-Step Guide

Imagine turning on your faucet and nothing comes out. No water for drinking, showering, or even flushing the toilet. For many homeowners relying on well water, this scenario is more than just an inconvenience – it’s a crisis. A failing or failed well pump can disrupt your entire life, rendering your home virtually uninhabitable. While calling a professional is always an option, the cost can be significant. Understanding how to replace your own well pump empowers you to regain control of your water supply and potentially save a substantial amount of money.

Replacing a well pump is undoubtedly a challenging task, often requiring physical strength, mechanical aptitude, and a thorough understanding of electrical safety. However, with careful preparation, the right tools, and a detailed guide, many homeowners can successfully complete the job. Knowing the ins and outs of your well system, diagnosing the problem, and understanding the replacement process are crucial for a smooth and safe installation.

What are the key things I need to know before tackling this project?

What size well pump do I need for my specific well depth and water usage?

Determining the right size well pump requires calculating your total dynamic head (TDH) and your desired flow rate (gallons per minute, or GPM). The TDH accounts for the vertical distance the pump must lift the water (pumping water level), pressure requirements at your house, and friction losses in the pipes. Once you know your TDH and desired GPM, you can consult pump performance charts to select a pump that provides the required flow rate at the calculated head.

To elaborate, first you need to determine your pumping water level, which is the distance from the surface of the ground to the water level in your well *while the pump is running*. This may be different from your static water level. Next, determine your pressure requirements. A typical household needs 40-60 PSI. Convert this pressure requirement to feet of head (PSI x 2.31). Then, estimate friction losses in your pipes, which can be obtained from pipe friction loss charts or calculated based on pipe diameter, length, and flow rate. Add your pumping water level, pressure head, and estimated friction losses to get your TDH. Finally, estimate your water usage. Consider the number of people in your household and their typical water consumption habits, including showers, laundry, dishwashing, and outdoor watering. Determine the peak demand, which is the highest amount of water you’re likely to use at any one time. This will give you your required GPM. Once you have your TDH and GPM, consult pump performance curves (provided by pump manufacturers) to select a pump that can deliver the required GPM at your calculated TDH. It’s often a good idea to slightly oversize the pump to account for future needs or unexpected demand.

How do I safely disconnect the electrical power to the well pump?

The safest way to disconnect electrical power to your well pump is by locating the dedicated circuit breaker for the pump in your main electrical panel and switching it to the “OFF” position. This will cut off the flow of electricity to the pump, preventing electric shock during the replacement process.

Before you even think about touching the well pump or any associated wiring, confirming the power is off is absolutely crucial. Don’t just rely on memory; double-check that you’ve identified the correct breaker. Sometimes, labels in electrical panels are inaccurate or outdated. Once you’ve switched the breaker off, use a non-contact voltage tester to verify that no electricity is present at the pump’s power wires or at the pressure switch. Hold the tester near the wires – it will usually light up or beep if voltage is detected. If you are uncomfortable working with electricity, or if you’re unsure which breaker controls the well pump, it’s best to call a qualified electrician. Working with electricity can be dangerous, and incorrect wiring can damage the pump or create a fire hazard. It’s always better to be safe than sorry. Never assume the power is off until you’ve verified it yourself with a voltage tester. Also, a good practice is to place a piece of tape over the breaker with a note saying “DO NOT TURN ON - WELL PUMP REPLACEMENT”.

What’s the best way to prime the new well pump after installation?

The best way to prime a new well pump after installation is to first ensure all connections are tight and the foot valve (if applicable) is submerged. Then, locate the priming port on the pump housing, remove the priming plug, and slowly pour clean water into the pump until it’s completely full and water overflows. Replace the plug and turn on the pump. If water doesn’t begin to flow within a minute or two, repeat the priming process. Persistent failure to prime indicates a leak in the suction line or a faulty foot valve.

Priming is essential because well pumps are designed to push water, not suck air. Without priming, the pump will spin and spin without drawing water from the well. The water introduced during priming creates the necessary vacuum to initiate the pumping action. It is also very important to ensure that you use clean water as you don’t want to risk introducing contaminants into your water system. When priming, patience is key. Depending on the depth of the well and the length of the suction line, it may take several attempts to fully prime the pump. If you’re repeatedly filling the pump and it quickly loses water, that’s a good indication of a leak on the suction side. Check all fittings, unions, and the foot valve. A small air leak can prevent successful priming. You can also use pipe dope or Teflon tape to ensure the connections are airtight.

What type of pipe connections are required and how do I make them watertight?

Replacing a well pump typically requires connections compatible with both the existing plumbing and the new pump, often involving threaded fittings, unions, and potentially solvent-welded joints depending on the pipe material (PVC, galvanized steel, or polyethylene). Achieving a watertight seal is crucial and involves using appropriate thread sealant (pipe dope or Teflon tape) on threaded connections and ensuring proper priming and curing when solvent welding PVC pipes.

For threaded connections, always clean the threads on both the male and female fittings. Apply Teflon tape in a clockwise direction, overlapping each layer, or use pipe dope according to the manufacturer’s instructions. Tighten the connection securely with appropriate wrenches, but avoid overtightening, which can damage the fittings. Unions are especially useful in well pump installations as they allow for easier future disconnection and maintenance without cutting pipes. If your system uses PVC piping, solvent welding (also known as PVC cement) provides a very reliable, watertight seal. Before applying primer and cement, ensure that the pipe is cut squarely and deburred. Apply primer to both the inside of the fitting and the outside of the pipe, then apply PVC cement liberally to both surfaces. Immediately insert the pipe into the fitting with a slight twisting motion and hold firmly for several seconds to allow the joint to set. Allow the joint to cure completely according to the cement manufacturer’s specifications before pressurizing the system. Failure to properly prime and cure PVC joints is a common cause of leaks. Finally, after installation, carefully inspect all connections for leaks while the pump is running. Even a slow drip can lead to significant water loss and potential damage over time. If you find leaks, tighten the fitting further (if threaded) or, if it’s a solvent-welded joint, it may require cutting out the faulty section and re-doing the connection.

How do I remove the old well pump if it’s stuck or corroded?

Removing a stuck or corroded well pump requires patience and persistence. Begin by thoroughly spraying penetrating oil (like WD-40 or PB Blaster) around the pump and any connections, allowing it to soak for several hours, or even overnight. Then, try gently rocking or rotating the pump to break any corrosion or sediment buildup. If direct pulling isn’t working, consider using a specialized pump removal tool or rigging a system with chains and a come-along, applying steady, controlled force. Avoid jerky, abrupt movements, as this can damage the well casing or the pump itself.

Removing a stuck pump can be one of the most challenging aspects of well pump replacement. Corrosion, mineral deposits, and sediment accumulation are common culprits causing the pump to seize within the well casing. The penetrating oil is your first line of defense. Reapply it liberally and frequently, allowing it to work its way into the tight spaces. Tapping lightly on the pump housing with a hammer (while protecting the pump with a block of wood) can also help to vibrate loose some of the corrosion. If the penetrating oil and gentle rocking don’t work, you’ll need to increase your leverage. A pump removal tool is designed to grip the pump securely and provide a mechanical advantage for pulling. Alternatively, you can create a similar setup using heavy-duty chains and a come-along attached to a secure overhead beam or A-frame. The key is to apply slow, steady pressure. Monitor the well casing for any signs of stress or movement, and stop immediately if you detect anything concerning. If possible, have a helper observe the pump and casing while you apply force, providing feedback on the pump’s movement and any potential problems. If you’re still unable to remove the pump after these attempts, it’s best to consult with a professional well contractor. They have specialized tools and experience dealing with severely stuck pumps and can prevent damage to the well. Trying to force the pump excessively can lead to a broken pump cable, a damaged well casing, or even a collapsed well, resulting in significantly more costly repairs.

What are the signs that my pressure tank also needs replacing?

Several telltale signs indicate that your pressure tank is failing and should be replaced alongside your well pump. These include waterlogged conditions (where the tank feels heavy and full of water even when it shouldn’t be), frequent short cycling of the pump (the pump turns on and off rapidly), fluctuating water pressure, and a complete lack of water pressure, even after the pump is running.

A waterlogged pressure tank essentially means the air bladder inside (or the air charge in bladderless tanks) has failed. This loss of the air cushion prevents the tank from effectively storing water under pressure. Consequently, the well pump has to work harder and more often to maintain water pressure in your home. Short cycling puts undue stress on the pump, shortening its lifespan and potentially leading to premature failure. If you notice your pump starting and stopping every few seconds or minutes while you’re using water, it’s a strong indicator of a faulty pressure tank.

Fluctuating water pressure, even with a functioning well pump, can also point to a failing pressure tank. The tank is supposed to provide a consistent pressure buffer, smoothing out the pump’s operation. If you experience noticeable dips and surges in water pressure when using faucets or showers, the tank may no longer be performing its intended function. Finally, a completely dead pressure tank will result in no water pressure at all, regardless of how well the pump seems to be operating. In this situation, replacing both the pump and the tank is often the most cost-effective solution, as the strain on the pump from a failing tank might have contributed to its own demise.

What safety precautions should I take when lifting and handling the well pump?

Safety is paramount when lifting and handling a well pump. Always disconnect the power supply to the pump at the breaker box before beginning any work to prevent electrocution. Wear appropriate personal protective equipment (PPE), including work gloves, safety glasses, and sturdy footwear. Utilize proper lifting techniques, such as bending your knees and keeping your back straight, to avoid injury. The pump can be heavy and unwieldy, so consider using mechanical assistance or getting help from another person to prevent strains or drops. Finally, be aware of surrounding obstacles and potential hazards like slippery surfaces or confined spaces.

Lifting a well pump can be surprisingly strenuous. Pumps are often heavy, especially if they’re full of water or if they’re constructed of cast iron or other dense materials. Working in potentially awkward positions near the wellhead makes it even more challenging. Before you even attempt to lift the pump, assess the weight and plan your moves. Enlist a helper if necessary, especially for deeper wells where the pump will have a considerable length of pipe attached. If working alone, consider using a pump puller or hoist to reduce the strain. A tripod hoist with a chain or cable can significantly simplify the lifting process, and often comes with safety features like weight limits and locking mechanisms. Beyond the physical strain, remember the electrical hazard. Even after disconnecting the power, double-check with a voltage tester to ensure the circuit is truly dead. Water and electricity are a dangerous combination. Also, be mindful of the materials you’re handling. Old pumps can be corroded, and the water within the well itself may contain bacteria or contaminants. Wearing gloves protects your hands from cuts, scrapes, and potential contamination. Finally, be aware of the area around the well. Make sure the ground is stable and free of tripping hazards, and be cautious of wildlife or insects that may be present, especially if the well cover has been removed for some time.

Well, there you have it! Replacing a well pump might seem daunting, but hopefully, this guide has made the process a little less intimidating. Thanks for taking the time to learn with us, and remember, safety first! We hope your water’s flowing smoothly now. Feel free to stop by again whenever you have another DIY project on your plate!