How to Install a Sump Pump Check Valve: A Comprehensive Guide

A sump pump is a crucial component of any home prone to flooding or having a high water table. It works by pumping excess water away from your foundation, protecting your basement from water damage. However, a sump pump is not complete without a check valve. This seemingly small component plays a vital role in the system’s efficiency and longevity. Without a check valve, water pumped out could flow back into the sump pit, causing the pump to cycle more often, wasting energy and shortening its lifespan. This comprehensive guide will walk you through the process of installing a check valve on your sump pump, ensuring your system functions optimally.

Why is a Check Valve Necessary?

Before diving into the installation process, it’s essential to understand why a check valve is necessary. Here’s a breakdown of its function:

• Prevents Backflow: The primary purpose of a check valve is to prevent water from flowing back into the sump pit after the pump has finished its cycle. When the pump shuts off, gravity will try to pull the water back down the discharge pipe. Without a check valve, all the pumped water would return to the sump, forcing the pump to run again shortly after, this rapid cycling increases wear and tear and reduces efficiency.
• Reduces Pump Cycling: By preventing backflow, the check valve reduces the frequency with which the sump pump needs to activate. This not only saves energy but also extends the lifespan of the pump, as constant start/stop cycles can significantly shorten its operational life.
• Protects the Pump: Frequent pump cycling puts unnecessary strain on the motor and other components. A check valve ensures that the pump only activates when the water level rises to a predetermined point, thus reducing the workload on the pump.
• Noise Reduction: The “water hammer” effect, which occurs when water rushing back down the pipe hits the pump, can create annoying banging noises. A check valve eliminates this problem.

Types of Sump Pump Check Valves

There are primarily two types of check valves commonly used in sump pump systems:

1. Swing Check Valve: This type uses a hinged flap that swings open to allow water to flow out of the pump and closes back up when the pump stops. They are the most common type due to their simple design and reliability.
2. Ball Check Valve: A ball check valve uses a ball that moves within the valve body. As water flows through the pipe, it pushes the ball out of the way, allowing passage. When the flow stops, the ball settles back down, sealing the valve. These are generally considered more reliable in handling debris.

For most residential sump pump systems, a swing check valve is sufficient and more economical. If your system frequently experiences debris, a ball check valve might be a better option.

Tools and Materials You’ll Need

Before you start, gather the necessary tools and materials. This will ensure that the installation process goes smoothly:

• Sump Pump Check Valve: Purchase a check valve that matches the diameter of your discharge pipe.
• Measuring Tape: To measure the length of pipe needed and make accurate cuts.
• PVC or ABS Primer and Cement: Depending on your pipe material. Ensure that the primer and cement are compatible with your pipe material, whether it’s PVC or ABS.
• Pipe Cutter: A ratcheting PVC cutter or a hacksaw will be needed for cutting the pipe.
• Gloves: To protect your hands.
• Safety Glasses: To protect your eyes from debris and chemicals.
• Clean Rags or Paper Towels: To clean up spills or excess cement.
• Optional – Sump Pump Hose Adapter: If you have a flexible discharge hose and are upgrading to a rigid PVC discharge pipe.
• Optional – Additional PVC Pipe: Depending on your system configuration, you may need a short length of additional pipe to properly integrate the check valve.

Step-by-Step Guide to Installing a Sump Pump Check Valve

Now that you have all the tools and materials prepared, let’s go through the step-by-step instructions on installing the check valve:

Step 1: Turn off the Power

Safety First! Before you do anything else, it’s imperative to disconnect the power to your sump pump. Unplug the pump from the electrical outlet. This is the most important safety precaution. You want to ensure you’re working in a completely safe environment and the pump will not turn on unexpectedly while you’re working. Water and electricity are a dangerous combination, so always double-check that the power is off before proceeding.

Step 2: Measure and Cut the Discharge Pipe

The next step is to determine the location where you want to install the check valve. Generally, it should be placed 6-12 inches above the pump discharge outlet. This is high enough above the sump pit floor to allow any accumulated water to naturally drain back into the sump pit when the pump stops but low enough to be easily accessed. Use your measuring tape to mark where you’ll cut the discharge pipe. You will need to remove a length of pipe that is equal to the length of the check valve, accounting for how much the valve will extend into the pipe on both ends. The precise measurement can vary depending on the valve’s specifics, so refer to the manufacturer’s guidelines if available, otherwise add the length of the valve and around 2 inches for installation on both ends.
Use a pipe cutter or hacksaw to cut the pipe at the marked spots. Make sure the cuts are square and clean, so the new connection can form a watertight seal.
If you have a flexible discharge hose, you will need to cut it and install a male threaded adapter to your hose using a hose clamp. This will allow you to connect the check valve.
Clean any debris from the cut pipe ends.

Step 3: Prepare the Check Valve and Pipe Ends

Before applying any cement, perform a dry fit. Place the check valve between the cut ends of the discharge pipe. Ensure that the valve’s directional arrow is pointing upwards, which indicates the correct direction of water flow. The pipe should easily fit into the ends of the check valve. This test will ensure you haven’t cut too much or too little pipe and familiarize you with how things will fit together. If the dry fit is satisfactory, you can proceed to the next step.
If the pipe ends are PVC, apply PVC primer to both the inside of the valve’s slip connections and the cut ends of the discharge pipe. Primer prepares the pipe and valve to form a strong, leak-proof connection, softening the plastic for optimal cement bonding. Apply the primer to each connection with an appropriate dauber or brush making sure each area is covered. Allow it to dry for the amount of time directed by the manufacturers instructions on the primer (usually a few seconds). Repeat on all areas to be connected.
If your pipes are ABS, you will use an ABS specific primer on the ABS pipe and the ABS connections on the check valve.

Step 4: Apply Cement and Connect the Valve

Apply the PVC cement to the same areas on which you applied the primer. It’s best to work fast when cementing the connections since it dries relatively quickly. Once cement is applied you will place the valve into position with the cut pipe and press firmly. Once in position, twist the joint about a quarter turn to get the cement to bond evenly and form a watertight seal. Hold the connections firmly in place for about 30 seconds to ensure the connection is secure, following the instructions provided by the cement manufacturer. After cementing the first connection, repeat the process for the second connection.

Step 5: Secure the Check Valve

Ensure that the check valve is securely and correctly oriented with the arrow pointing upward to allow the water to flow away from the sump pit when the pump is engaged. It’s important that the connection is flush and even for a proper seal. You may need to use a pipe support clamp to hold the pipe in position and prevent it from swaying or damaging the connection if your vertical discharge pipe is a bit unstable.

Step 6: Allow Sufficient Time to Dry

Let the cement dry and cure according to the manufacturer’s instructions. This will typically take a few hours. The exact drying time will vary depending on the brand of cement and the ambient temperature. Avoid applying pressure to the connections during the curing process. This will prevent leaks at the connections once the water starts to move through the pipes.

Step 7: Test the Installation

Once the cement has completely dried, plug the sump pump back into the electrical outlet. You should also place a gallon of water into the pit to ensure that the pump will activate. You’ll want to watch the pump discharge the water and verify the check valve stops the water from draining back down into the sump pit after the pump shuts off. Check for any leaks at the newly connected areas. If you find any leaks, double check the areas that need to be resealed. Turn off the power again and dry the area before reapplying the primer and cement. If the installation seems correct with no leaks, you have successfully installed your sump pump check valve.

Tips for Successful Installation

• Take your time: Do not rush any part of the installation. The connections are critical for preventing future issues and should be completed with care.
• Proper Fit: Ensure all pieces fit together snugly before applying cement. Any significant gaps can cause leaks.
• Manufacturer Instructions: Always adhere to the manufacturer’s guidelines for all products, including the check valve, primer, and cement.
• Ventilation: Work in a well-ventilated area, especially when using cement and primer, as their fumes can be harmful.
• Consult a Professional: If you are unsure of any step, or feel that this is beyond your skill level, don’t hesitate to call a qualified plumber for assistance.

Troubleshooting Common Issues

• Leaking Connections: If you notice leaks after the installation, turn off the power to the pump, dry the area completely, and inspect the connection carefully. It might be necessary to cut the connection and redo it with fresh primer and cement.
• Check Valve Not Functioning: If the water is still flowing back into the sump pit, double-check that the check valve’s arrow is pointing in the correct direction. It may be necessary to purchase and install a new valve if you have done this and are still seeing issues.
• Noisy Operation: A banging noise might mean the valve has been installed too far down and is causing the “water hammer” effect. You might have to raise the valve to a higher level in the discharge pipe.

Conclusion

Installing a sump pump check valve is a relatively straightforward DIY project that can significantly improve the efficiency and longevity of your sump pump system. By following the steps outlined in this guide and taking your time and safety into consideration, you can successfully complete the installation and ensure your basement remains dry and protected. Remember that a functional check valve is a worthy investment, preventing backflow, reducing pump cycling, and ultimately saving you money on repairs and energy costs. If you encounter issues or aren’t comfortable with the installation, it’s always best to consult a plumbing professional.