How to Know If Your RO Flow Restrictor Is Bad
Written by: Gene Fitzgerald // Last Updated: Jul 12, 2023
This page may contain affiliate links. If you buy a product or service through such a link we earn a commission at no extra cost to you. Learn more.
Flow restrictors are a vital part of any reverse osmosis system.
They are needed to control the amount of water that moves through the RO membrane and drain line at any one time to ensure you are getting enough good quality filtered water and not too much wastewater.
So what are the telltale signs that your flow restrictor might not be working as it should? Let’s find out.
Contents
show
Key Takeaways
- A key sign that your flow restrictor is bad is irregular water flow. This could mean there is too much wastewater going down the drain, not enough wastewater, or no wastewater at all.
- A bad flow restrictor may also affects permeate water quality and output.
Symptoms of Failure: How to Know If Your RO Flow Restrictor Is Bad
So, how to know if your RO flow restrictor is bad?
An irregular water flow from the RO faucet is one key sign that your flow restrictor might be malfunctioning. This could either be too much water or not enough, which in extreme cases could mean no water at all.
To determine whether the water flow is excessively high or critically low, there’s a straightforward method you can utilize. This involves detaching the drain tube from its fitting (at the drain saddle) and assessing the volume of water that drains out using a measuring cup.
For instance, if your flow restrictor is rated at 250 mL per minute, it should approximately allow this quantity of water to pass through within a single minute. However, keep in mind that this figure won’t be exact due to several contributing factors, such as feed water pressure, total dissolved solids, and temperature, among others.
Lots of Water Going Down the Drain (+ Only Small Amounts of Low-Quality Permeate Water)
If a reverse osmosis flow restrictor is too loose, it might not effectively control the water flow as it’s designed to. This malfunction can lead to considerable water waste.
When the restrictor doesn’t function correctly, the system allows more water than necessary to flow down the drain. This leads to excessive wastewater and affects the production of permeate water.
Due to the unrestricted flow, the system may produce only small amounts of this permeate water, and the water quality could be compromised because it hasn’t passed through the system at the optimal rate/pressure.
When the flow restrictor is excessively loose, it can cause additional issues with the RO system. For instance, the system may struggle to produce sufficient water and not shut off correctly. This can lead to complications such as water leakage and increased wear and tear on the system’s components.
No or Very Little Wastewater (+ Only Small Amounts of Low-Quality Permeate Water)
Just as constipation hampers the normal functioning of the digestive system, a blocked flow restrictor essentially ‘constipates’ your RO unit. This obstruction can negatively impact the quality of the processed water, making it unfit for consumption.
A clogged flow restrictor can harm other parts of the reverse osmosis system, too, particularly the RO membrane. When the flow restrictor is blocked, it can lead to premature clogging of the RO membrane. This reduces the membrane’s lifespan and may cause water to stop being produced completely.
One of the significant consequences of this scenario is an increase in the total dissolved solids value of the purified water. TDS refers to the total concentration of dissolved substances in water, including salts, minerals, and metals. High TDS levels can indicate poor water quality and make the water unsuitable for certain uses.
How Can RO Flow Restrictors Go Bad?
Though this is rare and usually does not happen, one way a flow restrictor can go bad is through clogging. This typically occurs when dirt, scale, or other impurities accumulate within the restrictor. Over time, these particles can build up and obstruct the water path, leading to reduced or completely blocked water flow. This situation can compromise the RO system’s functionality, leading to poor water quality and potentially causing the system to stop producing water.
Mechanical failures can also cause issues with the flow restrictor. For instance, the restrictor could become loose due to wear and tear or improper installation. When the restrictor is loose, it might not effectively control the water flow, leading to excessive water waste and reduced production of purified water.
Further Reading:
When Do Flow Restrictors Have to Be Replaced?
Certain manufacturers suggest replacing the flow restrictor every time the membrane is replaced. This recommendation is based on the fact that the flow restrictor and the membrane often work closely together, and any issue with one could potentially affect the other. However, this practice is not universally followed.
Most users prefer to continue using their flow restrictors until they fail, waiting for signs of trouble before initiating replacement – which is perfectly fine. It’s crucial to monitor the performance of your water filtration system regularly to catch and address any issues early.
How RO Flow Restrictors Work
A flow restrictor is a device that manages the speed at which water flows through an outlet, ensuring that systems like water filters and heaters operate efficiently and without damage. It works by adjusting a two-port valve to maintain a constant water flow, regardless of changes in water pressure. This is crucial for systems like reverse osmosis filters, which need specific contact time with the water to work effectively.
In a reverse osmosis system, the flow restrictor limits the amount of wastewater produced. It’s connected to the outlet tubing of the RO membrane to prevent the pressure inside from dropping too low, which would hinder the system’s function. It also stops the system from producing excessive wastewater, maintaining the necessary pressure on the membrane.
If you have any questions about how to know if your reverse osmosis flow restrictor is bad please don’t hesitate to leave a comment below!
About the Author Gene Fitzgerald
Information provided on BOS is for educational purposes only. The products and services we review may not be right for your individual circumstances.
We adhere to strict editorial guidelines. Rest assured, the opinions expressed have not been provided, reviewed, or otherwise endorsed by our partners – they are unbiased, independent, and the author’s alone. Our licensed experts fact-check all content for accuracy. It is accurate as of the date posted and to the best of our knowledge.