Welcome to the Reverse Osmosis Systems Troubleshooting Video Page. In this video Aquaman will explain the two most common problems with RO systems and how to troubleshoot them. 

Reverse Osmosis Systems Troubleshooting Video Transcript

Hey everyone, Aqua Man here with Water Wisdom sponsored by WaterFilters.NET. Today’s video is about reverse osmosis systems and, specifically about basic troubleshooting for your RO system. As you can see, RO systems are relatively complex machines. There are many water lines running different directions, and there are connections and valves and it can be a little bit intimidating. And we understand that and appreciate that, but essentially it’s really pretty simple to troubleshoot the most common problems that people find with their RO system. So, the first most common problem is water that runs continuously down the drain. Now, a system like this, all RO systems, work on a system of pressure, so when the tank is full and has full pressure, that triggers a mechanism called an ASO valve (Automatic Shut Off Valve). And it does just that: it automatically shuts off the flow of water, so that the reject water doesn’t continuously run down the drain. Let me show you how this works. Water comes into your system through the cold water supply in this orange waterline.

Now, the end of this waterline would be connected to a valve at the cold water line. So the cold water comes in to here, goes through the first pre-filter (that’s usually a sediment filter), then the second filter (that’s usually some form of a carbon filter), then the third stage, also typically a carbon filter, though that can vary, it’s not that important right now. Then out of that third final stage housing and then into this ASO valve. Then out of this ASO valve into the membrane and then the membrane has two outs. I’m gonna remove the membrane here and see if I can’t help you see what I’m seeing. There we go. There is two--there are two waterlines that exit the membrane. The black line is the drain line or the brine water, that’s the reject water. The white line is the good water and that’s going to go follow this line and it comes over here to this “T”, where it can go two places. It can go into the tank through this big thick white line, which ends up going in the tank, or it can go through this polishing filter and then to the faucet. This blue line leads to a faucet as you can see here. Ok now let me just set this back down. OK. There we go. So that’s the flow of water through the system. Now, what happens is the ASO valve is controlled by pressure from the tank. When the tank gets full, there’s about 35-40lbs of pressure that presses against the ASO valve and causes it to shut the flow of water off. If that doesn’t happen, then water continuously flows down this black line into the drain. And that’s a problem because you’re wasting water, that’s probably the worst problem, but also it’s an annoyance because it’s making noise and you can hear it running, even though it shouldn’t be.

So, if you hear water running down the drain, and you’re confident that your tank is full, and that the pressure in the tank is at least 30-40 PSI, preferably 35-40 PSI, and you can verify that by taking a typical tire gauge, you know, just an ordinary tire pressure gauge, and there’s a Schrader valve. You can see that Schrader valve on this tank here, there’s a Schrader valve, like a bike tire valve, on every tank. Take your pressure gauge;and measure the pressure when the tank is full. You can lift the tank and feel and tell that it’s full most likely. And then, if you have 35-40 and the tank is full, if water is running down the drain, you absolutely have a defective ASO valve and it needs to be replaced. OK? That’s the most common issue with RO systems. The second most common issue is low volume or low pressure at the faucet. So, you’ve gone to bed at night, and you’ve let the system sit operational all night, you know that in the morning you should wake up to a full tank of water and you’re ready to go to the faucet and push the lever and get a full, you know, 12 cups of water for your coffee maker, and you press the button and a trickle comes out. Or, maybe you get good pressure for a minute, the normal amount of pressure, but all of the sudden after one or two glasses of water, it starts to trickle off, and you’re thinking ‘where is my water?’ and ‘where is the normal water pressure that I’m accustomed to?’. This is an indication that there’s something wrong with your tank.

The most likely cause of this issue: low volume of water, or low pressure of water at the faucet, the most likely cause is something is wrong with the tank. You have to understand that inside this tank there is a bladder, an air bladder, that as the water builds and presses against that bladder increases the pressure that is in this tank. If that air bladder leaks or breaks, then there’s no way for the, for this uh, tank to build up any pressure. And so you’re not going to get water delivered to the faucet in the volume or the pressure that you’re accustomed to when the system is functioning correctly. So, very likely cause is a defective tank. How do you know? Check and make sure the tank is full. Again, lift the tank. You can tell the difference between an empty tank and a full 
tank. Also pinging the tank, with your finger, with your knuckles, with a wrench or something gently to hear, you can tell the sound of an empty tank versus a full tank. Then, take a tire pressure gauge again and measure the pressure on the Schrader valve and if the tank is full, you should get between 35 and 40 PSI. If you’re having problems with delivery or volume at the faucet, it’s very likely that it’s caused by a defective tank and you’re not going to have the pressure that you expect when you measure the pressure. You’re gonna get a very low reading and you might be able to, if it’s only a leak, you might be able to re-pressurize the bladder with a tire pump. Do this very cautiously. One pump at a time and re-check the pressure. You don’t just want to hook the pump up and start pumping; you’ll burst the bladder. It doesn’t take much air and so just one pump, re-check it, another couple of pumps, check it again and just verify what’s happening. It may be a busted bladder and you’re wasting your time. They’re only about $45 or $50 dollars to replace a tank like this, and so you know, really, when you think of the cost of a whole system, replacing the tank is an inexpensive way to resolve that issue.

Those are two of the most common problems with RO systems: defective ASO valve or a defective tank. I’m your host Aquaman and thanks for watching. 

See our entire selection of RO systems here.

Be sure to watch this highly informative slide show: Reverse Osmosis System Basics