a photo of a sink drain with attached drain saddle and drain line for a Reverse Osmosis System

Water is the essence of life, and ensuring its purity is vital for our health and well-being. This is where Reverse Osmosis (RO) systems come into play, playing a critical role in providing clean and safe drinking water to countless households and businesses. However, like any sophisticated system, RO systems can encounter issues as well, one of the most common being continuous water drainage. This not only wastes water but also reduces the efficiency of the system.

In a well-functioning RO system, water passes through the pre-filters, RO membrane, post-filters, storage tank, and drain line in a specific sequence. The system should not constantly drain water. Typically, the draining will occur during the filtration process and stop once the storage tank is full. The system is controlled by a series of valves that regulate the flow and pressure of water.

a photo of the NU Aqua Platinum Series 5 Stage 100GPD RO System with the tank

Regular maintenance is crucial for the longevity and efficiency of your RO system. It involves replacing filters and membranes at recommended intervals, checking for leaks, and ensuring all components are functioning correctly. Neglecting maintenance can lead to various issues, including the problem of continuous water drainage.

Common Causes of Continuous Water Drainage

Several factors could be responsible for the issue, and pinpointing the exact cause is the first step in resolving the problem. Here are the most common causes:

  1. Overfilled Storage Tank: The storage tank has a specific capacity, and if it gets overfilled, it can lead to continuous drainage. This usually happens due to a malfunction in the system's automatic shut-off valve or incorrect tank pressure.

  2. Malfunctioning Check Valve: The check valve prevents the backward flow of water. If it's malfunctioning or stuck, it could allow water to flow continuously into the drain.

  3. Faulty Shut-Off Valve: This auto shut off valve is designed to stop the flow of water once the storage tank is full. If it's not working properly, water will continue to pass through the system and down the drain.

  4. Clogged Filters or Damaged Membranes: Over time, filters and membranes can become clogged with impurities, affecting the system's ability to function correctly. This can cause an increase in water pressure and lead to continuous drainage.

  5. Pressure Issues in the Tank: The pressure in the storage tank plays a vital role in the proper functioning of your RO system. Too high or too low pressure can disrupt the water flow and cause continuous drainage.

Step-by-Step Troubleshooting Guide

  1. Checking the Pressure in the Storage Tank:

    • First, turn off the water supply to your RO system.
    • Drain all the water from the storage tank by opening the faucet.
    • Use a pressure gauge to check the air pressure in the tank. The ideal pressure should be around 7-8 psi when empty.
    • If the pressure is too low, use a bicycle pump or air compressor to add air. If it's too high, release some air.
    • Once adjusted, refill the tank and check if the issue persists.
  2. Testing system shut off:
    • Draw 2-3 glasses of water from the faucet. The system will start making water to fill the tank.
    • Turn OFF the tank's valve to mimic the tank full. To turn off the tank ball valve, simply turn the blue handle 90 degrees.
    • If your RO feeds multiple output points (icemaker, refrigerator, etc), shut OFF those lines.
    • Wait for 3- 5 minutes, then check to see if the drain water stops running.
    • Check drain water by either listening or actually pulling out the drain line to look at it. If drain water stops running, the RO is shutting off properly. Both the ASO valve and the Check Valve are working fine. Stop testing.
    • If drain water continues to run, then either the Check Valve and/or the ASO valve is defective. Proceed to Testing ASO and Check Valve.
  3. Testing ASO and Check Valve:
    • Make sure there is water in the tank (tank not empty).
    • Remove the Black drain line from the drain saddle, this is so you can check drain flow drainage.
    • Turn OFF the Cold feed water supply.
    • Turn ON the tank ball valve.
    • Check the Black drain line to see if there is any water draining out from this line.
    • If water does drain out from the black line then this water is coming from the storage tank. This means the Check Valve is broken, it is allowing the water in the tank to backflow out into the drain line.
    • If no water drains out from the black line (no drain water running), that means the Check Valve is OK. The system's non-shut off is caused by a defective ASO valve, not caused by the Check Valve.
    • Checking and Replacing Filters and Membranes:

      • Remove and inspect each filter and the RO membrane.
      • Look for signs of clogging or damage. If they are old or heavily used, it’s best to replace them.
      • Install new filters and membranes, ensuring they are seated properly.
    • Ensuring Proper Connections and No Leaks:

      • Check all connections and fittings for tightness.
      • Look for any signs of leaks or drips. Even a small leak can cause the system to malfunction.
      • Tighten any loose connections and replace damaged parts as necessary.

    After performing these steps, turn the water supply back on and check if the system is still draining continuously. It may take a few hours for the system to stabilize, so be patient.

    Preventive Measures and Regular Maintenance

    To ensure the longevity and optimal performance of your Reverse Osmosis system, regular maintenance and preventive measures are essential. By staying proactive, you can often prevent issues like continuous water drainage before they start. Here are some key tips to help you maintain your RO system effectively:

    1. Routine Maintenance Schedule:

      • Filter Replacement: Pre-filters and post-filters should typically be replaced every 6 months. The frequency can vary depending on your water quality and usage.
      • Membrane Replacement: RO membranes usually need replacement every 12 months, but this can vary based on water quality and the amount of water filtered.
      • System Inspection: Perform a thorough inspection of the system at least once a year. Check for any leaks, wear and tear, or other signs of damage.
        a photo of the NU Aqua Platinum Series Complete Filter Replacement Set With Membrane
    2. Tips for Preventing Common Issues:

      • Monitor Water Pressure: Ensure that your water pressure is within the ideal range for your RO system. Extremely high or low pressure can lead to various issues, including continuous drainage. For example, the NU Aqua Platinum Series 5 Stage 100GPD RO System w/ No Pump, incoming water pressure must be between 45 PSI and 80 PSI.
      • Check for Leaks Regularly: Small leaks can lead to bigger problems. Regularly inspect your system for any signs of leaking.
      • Clean and Sanitize the System: Periodically cleaning and sanitizing the system can prevent bacterial growth and ensure the purity of your water.
    3. Importance of Using Quality Parts and Filters:

      • Using high-quality replacement parts, including filters and membranes, is crucial for the efficiency and longevity of your RO system.
      • Avoid generic or low-quality parts as they may not be as effective and could lead to more frequent issues.

    When to Seek Professional Help

    While many issues with your Reverse Osmosis (RO) system can be addressed through DIY troubleshooting and regular maintenance, there are times when professional help is necessary. Understanding when to call in the experts can save you from further complications and ensure the longevity of your system.

    Identifying Issues That Require Professional Assistance:

    1. Complex System Problems: If you’ve followed the troubleshooting steps and the problem persists, it might indicate a more complex issue within the system.
    2. Frequent or Recurring Issues: When problems occur frequently or reoccur soon after troubleshooting, it may be a sign of an underlying issue that requires professional expertise.
    3. Installation and Upgrades: If you are installing a new system or upgrading your existing one, professional installation ensures it's done correctly and efficiently.

    Benefits of Professional Servicing and Maintenance:

    • Expert Diagnosis: Professionals have the experience and tools to quickly diagnose and resolve complex issues.
    • Quality Repairs: They can provide high-quality repairs and parts replacements that might not be easily accessible to homeowners.
    • System Optimization: Experts can optimize your system for maximum efficiency and water quality.
    • Peace of Mind: Knowing that your system is in good hands can provide reassurance and confidence in your water quality.

    Finding a Reliable Service Provider:

    • Look for service providers with good reviews and experience with RO systems.
    • You can ask for recommendations from friends or family who have RO systems.

    Continuous water drainage in an RO system can be a nuisance, but with the right approach, it is often a solvable problem. By understanding your system, performing regular maintenance, and knowing when to seek professional help, you can ensure the efficient and effective operation of your RO system.

    We invite you to visit NU Aqua Systems for more information, assistance, and access to a range of products designed to enhance and maintain the quality of your RO system.

    Thank you for following our guide, and here's to the continued purity and safety of your drinking water!