Reverse osmosis systems are fairly complicated because of the several water lines that run in various directions. There are also different valves and connections that may lead consumers to believe that fixing any problems is difficult. The truth is, fixing RO problems is easy. You only need to read and understand the manual to know how it works and to fix it.
The most common issue raised by consumers is the continuous drain water from the reverse osmosis system. This problem should not happen because RO systems are designed to switch off automatically once the storage tank is full. All reverse osmosis work on a system of pressure, so it follows that when the storage tank is full and has full pressure, the automatic shut off (ASO) valve will shut off automatically. When the ASO valve shuts off, the reject water will not drain constantly, but if it fails to switch off even after the tank is full, then the drain water will continue to flow. If the water continues to drain, the pre-filters and the membrane will be damaged and you will have to pay higher water bills.
If the tank is full and the tank’s pressure is at least 30-40 PSI (35-40 PSI is preferred) but you hear water flowing down the drain –
- Check the typical tire gauge. Remove it the same way you would remove an ordinary tire pressure gauge. And you will see a Schrader valve that looks like a bike tire valve.
- Get your tire pressure gauge to measure the pressure once the storage tank is full. Another way to check if the tank is full is to lift it. This will let you feel it is indeed full.
Reasons why an RO System Drains Constantly
Faulty or Damaged Automatic Shut Off(ASO) Valve or Check Valve
If the tank is full and the pressure is between 35-40 PSI, but you still hear water flowing down the drain – your ASO valve is definitely damaged or defective. So, you need to replace it.
- Conduct a switch off test to check if the valve is damaged or faulty. These valves regulate the shut off function of RO systems. Read your RO manual to identify the location of these valves. Your reverse osmosis system will not shut off automatically if any of these valves is damaged, defective or clogged, so the RO system will drain constantly.
Damaged or Defective Storage Tank.
Low Water pressure. The tank contains an air bladder, so when the tank is filled with water, it puts pressure on the bladder causing increased pressure in the tank. If the air bladder breaks or leaks, the tank will not be able to accumulate any pressure. This results in getting less water from your tap because of the small volume or pressure. To check if the water pressure is low at the faucet –
- Examine if the storage tank is full. Lift the tank and feel if it is full. It is easy to identify a full storage tank to an empty tank if you do this. You can also knock on the tank by using your fingers, knuckles or a wrench. The sound produced from knocking on the tank will tell you if it is full or empty.
- Get a tire pressure gauge. Measure the pressure on the Schrader valve. A 35 to 40 pressure means the tank is full.
Low Volume of Water. A defective or damaged tank will have a low volume of water and will yield a little amount of water.
- If your tank has a leak, re-pressurizing the bladder with a tire pump is enough to solve this problem. Do this carefully, though, and pump the bladder in sequence, and check the pressure. The bladder will burst if you attach the pump and begin the pumping. It should be one pump at a time then check it. Follow this with a couple of pumps then check. If the bladder is broken, there is no use pumping it. Buy a new tank. It roughly costs $45 or $50. Buying a new tank is the most economical thing to do on solving this problem.