Malfunctions of reverse osmosis systems

Introduction

Reverse osmosis filters have become commonplace in Ukrainian kitchens. With their prevalence, many questions have arisen about malfunctions in the operation of these filters. Let's delve into the reasons behind their occurrence.

Causes of Reverse Osmosis Filter Malfunctions

1. The service life specified in the passport has expired, and the vessels, hoses, and fittings have worn out. The service life varies among manufacturers. As for Ecosoft filters, the service life of our reverse osmosis systems is five years.
2. Low system quality. Such issues are typical for "no-name" systems of Chinese production. So, if you are pleased with the cost of the system, it is worth reading reviews about the product beforehand.
3. Manufacturing defects. Unfortunately, this factor occurs with any manufacturer.
4. Malfunctions usually occur immediately after purchasing the filter and are covered by the manufacturer's warranty.

Operation and maintenance-related problems.Now let's try to thoroughly understand the most common problems that arise. Why is the water filter leaking, the taste is spoiled, and the tank fills slowly?

Low pressure from the faucet in the reverse osmosis system

1. Reverse osmosis system faucet. Limited water supply.If you have recently installed or performed planned maintenance, check if the pipes are not kinked and if the tank valve is fully open.
2. Low pressure in the pipeline. If the pressure in your pipeline is below 3 atm, then it will be insufficient for the filter to work properly. The tank will fill very slowly, and a lot of water will be discharged into the sewer. This problem can be solved by installing a pump.
3. Untimely replacement of pre-filtration cartridges or membrane element.After the expiration of the service life or increased water consumption, the membrane element becomes clogged with slime, causing the filter to fill the tank slowly. Untimely replacement of cartridges will result in unfiltered water entering the membrane. This, in turn, will lead to its accelerated clogging. If you replace the membrane and cartridges in a timely manner but this happens regularly, we recommend replacing the 1-2-3 kit more often. We have written about this in detail earlier.
4. Low pressure in the storage tank. The pressure should normally be 0.4 - 0.6 atm (bar). If the pressure does not meet the requirements, it is necessary to pump it using a pump. This service is provided by the service engineer.

Why is the water filter leaking?

Filter leaksWater filter leaks can occur for several reasons. Before fixing the leak, it is necessary to understand why it is happening.

Incorrect connection or maintenance.

1. Such malfunctions usually occur immediately after manipulation of the system by hand or after the arrival of a technician. To fix such faults, it is enough to carefully inspect the filter, identify the leak, and seal it at the found point. The main places of leakage can be clips on hoses, drainage, and joints between vessels and bases. To fix this problem, you can disconnect the filter, disconnect and reconnect the connections.
2. Pressure spikes in the system. Most systems allow a working pressure of up to 6 atm (bar). If your water supply system has pressure fluctuations, it is worth installing a reducer to protect the filter. After installing the reducer, check all fittings and connections.
3. Wear of the sealing gasket between the vessel and the head. This happens when the installation has completed its service life; to replace it, you should purchase a gasket or call a service engineer who will install it.
4. Mechanical damage. This can occur during transportation or improper maintenance or installation.
5. Low-quality components. This often happens in "no-name" systems. Usually, these inconveniences can be resolved by the service department.

To find out why the water filter burst, you should always check factors 2, 4, or 5. Usually, they are the cause of the malfunction.

High noise level

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If your system is making a lot of noise, this could be due to:

1. Air in the autoregulator - this problem will resolve itself after a while.
2. Increased pressure at the system inlet. In this situation, it is recommended to install a check valve at the entrance to the apartment or directly in front of the system.
3. Low pressure level in the tank.

Why does not turn on the reverse osmosis pump

The pump for reverse osmosis filters is designed to increase the pressure directly in front of the filter, it allows you to increase the performance of the filter and reduce the flow of water into the drain. The reasons why the pump does not work may be:

1. low pressure in the pipeline - each pump has a minimum inlet pressure, usually 1.5 - 2 atm, if it is lower, the pump will not work;
2. pinching of the hoses, this problem is usually encountered immediately after replacing the cartridges;
3. lack of power supply to the pump - check the mains connection.

Key Components and Their Role in RO System Troubleshooting

1. Filters
   The prefilters, usually sediment and carbon filters, are vital for protecting the RO system. Sediment filters catch particles that could clog the system or damage the flow restrictor, while carbon filters remove chlorine, which can damage the RO membrane. Postfilters add a final polish, ensuring fresh-tasting water by reducing any residual odors or flavors before the water reaches your faucet. If filters become clogged or ineffective, water flow may slow, or the membrane could become compromised, leading to reverse osmosis problems.
2. Membrane
   The RO membrane is the core component responsible for removing dissolved solids from water, operating under pressure. This pressure pushes water through the membrane while rejecting contaminants. Insufficient pressure will reduce the production rate and the efficiency of total dissolved solids (TDS) rejection, which is crucial for the system’s performance. Troubleshooting reverse osmosis system issues often involves checking for adequate feed pressure.
3. Flow Restrictor
   The flow restrictor is designed to create backpressure to aid water flow through the membrane efficiently. Incorrect flow restrictor sizing or blockages can cause either excess water waste or insufficient pressure for the RO membrane. This can lead to inefficiency or even system shutdown, which are common water filter osmosis reverse problems.
4. Check Valve
   Positioned at the outlet of the membrane, the check valve prevents backpressure from affecting the membrane, protecting it from potential damage due to reverse flow. If the check valve fails, it could result in reverse osmosis not working, as the system cannot maintain the required pressure to activate the automatic shut-off (ASO) valve.
5. ASO (Automatic Shut-Off) Valve
   The ASO valve controls water flow based on the pressure in the storage tank. When tank pressure reaches approximately two-thirds of the inlet pressure, this valve closes, stopping production. If the ASO valve malfunctions, the system may continue running, wasting water or causing reverse osmosis noise.
6. Storage Tank
   The storage tank in an RO system holds filtered water and delivers it on demand. Loss of air pressure or a damaged diaphragm can lead to low or no water flow at the faucet. Troubleshooting reverse osmosis system problems often includes checking the tank’s air pressure, as reduced flow can indicate a pressure issue.
7. Drain Saddle
   The drain saddle directs wastewater from the RO process to the drain line. Blockages here can prevent proper drainage, leading to pressure build-up or even overflow.
8. Air Gap
   The air gap provides a physical break between the RO system and drain connection to prevent backflow contamination, a key consideration in plumbing codes. When troubleshooting, ensure this gap is clear to avoid system shutdown or contamination risks.
9. Feed Pressure
   Proper feed pressure is essential for optimal RO system operation. If feed pressure is too low, TDS rejection and water production drop, impacting efficiency. High TDS levels can also challenge the system’s performance, potentially causing RO system troubleshooting concerns like low output.

Understanding these components and their functions can aid in diagnosing issues such as RO system not working, troubleshooting reverse osmosis problems, and addressing specific issues like system noise and reduced water output.

Why water is constantly flowing into the drain

1. The prefilter membrane or cartridges are contaminated. Contamination reduces the filter's throughput or simply clogs it, so that the pressure in the pipeline cannot force water through the membrane. In this situation, scheduled maintenance will solve everything.
2. Low pressure at the inlet to the system also makes it impossible for the liquid to pass through the membrane element and large volumes of water are drained into the sewer. At the same time, the tank is slowly taking on water.
3. Autoregulator malfunction. To check this point, you need to turn off the tap on the tank. After 2 to 5 minutes, the autoregulator should shut off the water supply to the system. If this does not happen, contact a service centre to replace the autoregulator.
4. Malfunction of the membrane check valve. If this part is broken, then even if the tank is full, water continues to flow to the membrane and bypass it to drain into the sewer.
5. Low pressure in the tank.
6. Clogged or faulty flow restrictor. It should be inserted into the black tube at the outlet of the membrane holder. If the part is missing, it is likely that it has been washed down the drain and a new element needs to be installed. It is also possible that it is located near the drainage clamp. In this case, flush it and install the tube in the flow restrictor closer to the membrane holder.

How to Troubleshoot Common Reverse Osmosis System Issues

Encountering issues with your reverse osmosis (RO) system? Common problems include low water flow, leaks, odd noises, or a change in water taste or odor. Below are some straightforward troubleshooting steps to help identify and resolve these problems.

1. RO Storage Tank Issues

If there’s no water flow, first check if the tank is filled. Open the faucet and check the flow. Ensure the tank’s valve is open (handle aligned with tubing). Next, measure the tank’s pressure with a tire gauge. If the pressure is below 5-7 psi, add air using a pump until it reaches this range. If water sprays from the air valve, the diaphragm has likely failed, and the tank needs replacing.

For tanks with pressure above 20-25 psi and no water flow, confirm tank functionality by closing the tank valve, disconnecting the tubing, and opening the valve over a bucket to observe flow. If the tank isn’t dispensing water, check if the post-filter is clogged.

2. Little or No Water Output

Low or nonexistent water flow from the RO system can have multiple causes:

• Permeate flow test: Close the tank valve and open the faucet to observe a steady drip. Measure the flow over 60 seconds.
• Drain flow test: Disconnect the drain tubing and collect water for 30 seconds in a container, doubling the result for flow per minute.
• Feed pressure: If your system is newly installed, check that the feed pressure is sufficient.
• Tank pressure: With a tire gauge, ensure the tank pressure is between 5-7 psi.

Double-check all connections, as an incorrect setup can reduce water flow significantly.

3. Continuous Drain Flow

A constantly running drain often signals the automatic shut-off (ASO) valve isn’t closing. This could be due to issues with the membrane, flow restrictor, check valve, or the tank itself. To troubleshoot, close the tank valve and observe if the ASO valve eventually stops the drain flow. Causes include:

• Faulty flow restrictor: Excessive drain flow suggests a missing or broken flow restrictor.
• Tank pressure issues: Inadequate pressure in the tank can prevent ASO from closing.
• Stuck ASO valve: Disconnect the valve, release any trapped pressure, and reconnect.
• Leaking check valve: With a full tank, open the faucet, close the water supply, and check if water continues to drain—indicating a leaking check valve.

4. Noisy Drain Gurgling

If your RO system produces loud gurgling sounds, it may be due to excessive drain flow. Relocate the drain saddle to a crossover pipe for noise reduction, as under-sink placement can amplify sound. Running the drain flow test can confirm if excessive flow is the culprit. Note that some noise is typical for an RO system when the tank fills.

5. Off-Tasting or Smelly Water

Odd tastes or odors are usually due to old filters, tank contamination, or membrane failure. For RO systems connected to well water, hydrogen sulfide (often smelling like rotten eggs) can concentrate in the system. Replace filters, sanitize the tank, and test the membrane for high TDS (total dissolved solids) breakthrough if bad odors persist.

6. Leaking Fittings or Housing

Leaks often occur due to issues with O-rings. Worn or misaligned O-rings can cause leaks when the filter housings are reinstalled. Keep spare O-rings and silicon lubricant available.

Causes of Fitting Leaks:

• Incomplete Tubing Insertion: Insert the tubing about 1 inch into the fitting for a proper seal.
• Misaligned Cuts or Scratches on Tubing: Tubing should be cut cleanly and without deep scratches. Replace tubing if worn to prevent leaks.

7. Leaks from Air Gap Faucets

Newly installed systems often encounter air gap faucet leaks. Ensure the tubing between the air gap and the drain saddle is as straight as possible. Bends in the tubing can cause overflow. Occasionally, Tomlinson faucets can leak at the neck; inspect the O-ring for damage and apply vegetable oil to re-seat it properly.

How to Test RO System Flow Rate

How to Test Permeate Flow Rate

To assess membrane performance, test the permeate flow rate. For most RO systems connected directly to a tank, the membrane produces the product water. To conduct this test, close the tank valve and open the faucet. The membrane production should flow directly to the faucet. Once the water begins to drip consistently, collect it in a measuring cup for 60 seconds.

Under normal feed pressure and water temperature, the volume collected in 60 seconds should match the values in the chart below.

How to Test Drain Flow Rate

To check if the flow restrictor is providing sufficient pressure, disconnect the drain line from the drain saddle. Place the open tube into a bucket and measure the water with a large measuring cup for 30 seconds. Multiply the result by two to get the drain flow rate, then compare it to the chart above.

Water does not flow into the drainage

This indicates that the system is not working at all. This can be caused by a clogged flow restrictor that needs to be removed and washed, or an incorrectly installed drainage clamp. In the second case, you need to check that the hole in the pipe and the installed clamp match.

How to repair the tap for the drinking water filter?

Our customers rarely complain about the breakdown of water taps, this usually happens after many years of service. If your drinking water tap has started to leak, we recommend replacing it. If you decide to make repairs:

• remove the cap from the tap valve;
• use a Phillips screwdriver to unscrew the screw;
• remove the valve from the tap base;
• remove the lock washer;
• unscrew the taps with pliers;
• remove the tap coupling and remove all parts from it;
• remove the rubber bands from the central metal part and replace them (diameter of the rubber bands is 6 mm);
• clean all parts;
• lubricate the tap head;
• assemble the tap in reverse order.
  

Poor taste of water

An unusual smell or taste in the water usually occurs when the carbon post-filter has reached the end of its useful life. In this case, you can simply replace it.

The second reason is contamination of the system or tank. This usually happens in the case of improper maintenance. It is necessary to perform scheduled maintenance and disinfection of the system.

Turbidity after cleaning

This is due to the fact that the water is saturated with air. This is not an indication of a malfunction and goes away after one or two weeks after the filter is installed. To make sure that it is air, pour water into a glass and let it stand for 5 to 10 minutes.

It is worth noting that this is possible in winter, when the temperature difference between the water and the environment can vary greatly.

If you have any troubles not related to those listed in the list, write about them in the comments.

And don't forget that Ecosoft offers not only high-quality filters, but also a high level of service.