How to Install an RO Auto Shut-Off Valve (ASO)
Written by: Gene Fitzgerald // Last Updated: Aug 25, 2023
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Do you have an issue with your existing ASO valve and know it needs to be replaced?
Or does your reverse osmosis system not have an automatic shut-off valve yet and you want to install one?
Don’t worry, you don’t have to call a plumber. Here is how to install an RO auto shut-off valve in a few simple steps.
Contents
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Key Takeaways
Follow these steps to install an RO ASO valve:
- Close the water supply and storage tank valve.
- Drain all remaining water.
- Connect the water supply inlet tube into the ASO valve’s ‘in’ port and the outlet tube to the ‘out’ port.
- Connect the permeate in and out lines to the ASO valve’s ‘permeate in/out’ ports.
- Turn on the water supply and check for leaks.
How to Install an RO Auto Shut-Off Valve
So, here is how to install an RO ASO valve:
- Ensure the water supply is switched off at the feed valve of your reverse osmosis system.
- Close the storage tank valve.
- Open the RO faucet and drain any remaining water.
- The ASO valve needs to be connected to the water line before the RO membrane and the correct tubing after said membrane.
- Connect the water supply inlet tube coming from your pre-filters into the ASO valve’s ‘in’ port and the outlet tube to the ‘out’ port (see diagram below).
- Connect the incoming permeate line (clean water) to the ASO valve’s ‘permeate in’ port and fasten the outgoing permeate line to the ‘permeate out’ port. Ensure that the connections are secure by pulling back.
- You probably need to cut your existing tubing if you hadn’t installed an ASO valve before. If required, adjust the tubing to a suitable length ensuring enough slack to fit the ASO valve without creating kinks that may cause blockages or complications later down the track.
- Gently turn on the water supply to the RO system and inspect the ASO valve connections for leaks. If leaks are detected, turn off the water supply and adjust the tubing connections before retesting.
- Once leak-free connections are confirmed, let the RO system operate for a short time to ensure the ASO valve is working correctly and stopping water flow when the storage tank is full.
Reverse Osmosis ASO Valve Installation Diagram
Here is a diagram showing where to put an RO ASO valve.
As shown in the diagram, the ASO valve should be installed between the RO pre-filters and the RO membrane, and the RO membrane and the post-filter/storage tank.
The top left side of the ASO valve is connected to the water coming from the pre-filters and exists the valve to move to the RO membrane. Once it moves through the membrane, it passes to the bottom right side of the shut-off valve, moving through and exiting the bottom left to flow to the storage tank.
Further Reading:
How Does a Reverse Osmosis Automatic Shut-Off Valve Work?
The automatic shut-off valve regulates water flow and usage in the RO system, serving one crucial function: It stops more water from entering the system once the storage tank is full.
The automatic shut-off mechanism comprises two sections and a diaphragm. The diaphragm’s movement within the housing depends on the pressure difference between the incoming water and the backpressure from the tank. When the storage tank’s pressure surpasses around 2/3 of the inlet pressure, the diaphragm pushes up, halting the feed water flow. The flow will only resume once the storage area pressure decreases due to water withdrawal from the RO faucet.
Without the automatic shut-off valve, water would continue to flow into the system, through the pre-filter stages, and down the drain causing wear and tear on components and wasting water.
If you have any questions about our RO auto shut-off valve installation guide please don’t hesitate to leave a comment below!
About the Author Gene Fitzgerald
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