Waste Water Not Coming from Your RO System? Here Is What to Do!
Written by: Alexandra Uta // Last Updated: Apr 20, 2023
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Reverse osmosis systems produce waste water no matter how efficient. It’s simply part of the purification process.
But what happens when your RO system stops producing waste water? We know it can be confusing and worrisome, but don’t panic.
In this article, we’ll discuss possible reasons your RO system is not producing waste water and provide practical solutions to help you get your system back on track.
Contents
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Key Takeaways
Here is what to do if no waste water comes from your RO system:
- Turn on your system’s water supply.
- Replace clogged filter elements.
- Ensure you fixed the RO membrane correctly.
- Unclog or change bad tubing.
- Unclog or replace a bad flow restrictor.
Waste Water Not Coming From Your RO System? Here Is What To Do!
There are several reasons why your RO system may stop releasing waste water, and to fix your system, you first need to figure out the cause of the problem.
Troubleshooting: Why Is There No Waste Water Coming From Your RO System?
We’ve explained five possible reasons for your waste water troubles. Check your RO system to see which one applies.
1. Water Supply Turned Off
The RO system can no longer receive feed water if the water supply is turned off. And if there’s no feed water to filter, the RO system cannot release waste water either. Check your water supply valve to see if it’s closed, open it.
2. Clogged Pre-Filters
If the pre-filters are clogged, your RO system will produce a lot less or even no water. So there’ll be less water coming from your faucet, less water in the RO tank, and less waste water sent down the drain.
Your pre-filters could get clogged if you haven’t replaced them in a while (most pre-filters need to be replaced every 6-12 months, but check with the manufacturer to be sure).
3. RO Membrane Not Installed Correctly
If you’ve recently replaced the reverse osmosis membrane, check if it sits correctly. Common installation mistakes like fixing the membrane backwards and leaving the end caps on can prevent your RO system from producing waste water.
4. Clogged Tubing
If the feed or drain tubing is cogged, your RO system may stop producing waste water.
- Check the feed water tubing for clogs by disconnecting the feed line where it connects to the RO inlet. Remember to turn off the water before disconnecting the tubing and point the tubing in a bucket when you turn the water back on (to prevent spills). With the tubing disconnected, you’ll be able to determine if the system is still receiving water or not.
- Your drain tubing could also be clogged, preventing any waste water from flowing down the drain. Check and clean if need be.
5. A Bad Flow Restrictor
The flow restrictor maintains pressure within your reverse osmosis system and prevents excessive waste water production. But if the flow restrictor is clogged (with sediments and dirt), water cannot flow through the drain pipe at all — meaning no waste water from your RO system.
How do you know if your flow restrictor is bad? Remove the flow restrictor from the drain line. If waste water starts to flow, the flow restrictor is the problem. Also, try blowing air through the disconnected restrictor. If the air doesn’t pass through it, the restrictor is clogged.
How to Fix
Depending on the cause, here’s how to fix waste water not leaving your RO system:
1. Turn On Your RO System’s Water Supply
If the problem is a closed water supply valve, open your RO water supply by turning the RO valve clockwise (to the right).
2. Replace Any Clogged Filter Elements
If you have clogged filter elements, it’s time to replace them. Not sure how to replace them? Follow the steps below:
- Clean your hands, turn off the water supply, and close the storage tank valve.
- Turn on the RO faucet. Leave it open until all present water has drained out.
- Remove a filter housing by turning it clockwise. If the housing contains debris, clean it with warm water and liquid soap.
- Take out the old and slot in the new filter element and make sure the O-rings are in the correct position.
- Screw back the housing, and make sure it’s tight enough.
- Turn the water supply back on, and let the RO tank fill up. Check for leaks as the tank fills.
- Flush out the water in the tank and let the tank fill up again. Discard the water one more time before resuming using your RO system.
3. Make Sure RO Membrane Is Installed Correctly
Here’s how you install an RO membrane correctly:
- Clean your hands, turn off the water supply, and close the storage tank valve.
- Open the RO dispenser and wait.
- Once the flow has stopped, detach the tubing from the membrane housing cap. Press and hold the collect against the quick-connect fitting to do this.
- Turn the membrane cap clockwise to remove it. If it doesn’t turn quickly, use a wrench.
- Remove the old membrane and clean the housing to remove lurking debris.
- Slot in the new RO membrane and push it all the way down until it sits tightly in the housing. Be sure that the part with the two black O-rings goes in first.
- Screw the membrane housing cap back on.
- Now, reconnect the pipe you removed earlier to said cap.
- Turn the water supply back on, and let the RO tank fill up. Check for leaks as the tank fills.
- Drain the first two water batches by opening the RO faucet. Resume using your RO system with the third water batch.
Note: The product manual will likely contain a more detailed and specific guide to replacing your RO membrane, so that’s the best place to look for instructions.
4. Unclog or Replace Bad Tubing
You can either clean bad tubing thoroughly to remove clogs or simply replace it.
- For cleaning, start by shutting off your water supply and draining the water completely to clear the tubing.
- Remove the tubing in question.
- Then, pour a cleansing solution down the pipe. There are a couple of options here — hot water, commercial cleaning chemicals, or the baking soda + vinegar + hot water method. These solutions are best for slightly blocked tubing with water running slowly through them, not wholly clogged pipes. Using a plunger or drain snake is best to remove debris from a totally blocked tube.
5. Unclog or Replace Bad Flow Restrictor
If you’ve confirmed that the RO flow restrictor has issues, it’s time to replace it. Ideally, you should replace the flow restrictor once a year. Replacing a flow restrictor is simple; detach the hose from the old restrictor, remove the old restrictor, fix the new flow restrictor, and reconnect the hose to it. Of course, you should shut off the water supply and drain the system before replacing the restrictor.
Further Reading:
Reverse Osmosis System Components Explained
Many components and elements make up a reverse osmosis system, and if you’re trying to fix yours, it can get confusing. Lucky for you, we’ve explained all the components of an RO system so you can find and fix the parts that may be obstructing your RO waste water flow.
Feed Water Valve
The feed water valve links your sink’s water (unfiltered) to the first filter in the RO system.
Pre-Filter(s)
Pre-filters treat your water before it reaches the primary RO membrane. They eliminate dirt, sediment, chlorine, and chloramine among other stuff that would otherwise damage the RO membrane.
RO Membrane
The RO membrane is the primary filtration media in an RO system. Its tiny pores block most water contaminants.
Storage Tank
It stores your filtered water so you can access it whenever you want. When you open your RO faucet, water flows from the tank through a post-filter and out of your RO faucet.
Post-Filter
A post-filter gives your water the final treatment after the RO membrane. Most post-filters improve water taste and smell.
Check Valve
The check valve protects the RO membrane. It prevents pressure from the storage tank from pushing the water back to the membrane. Such backward water flow could cause damage.
Flow Restrictor
The flow restrictor maintains pressure within the RO system by preventing too much waste water from flowing down the drain line.
Drain Line
Simply put, the drain line discharges RO waste water.
RO Faucet
This is perhaps the component you’re most familiar with. The RO faucet dispenses the finished work — clear, RO-purified water.
If you have any thoughts about the question, why is there no waste water coming from my RO system, please don’t hesitate to leave a comment below!
About the Author Alexandra Uta
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