Hydronix ASV-14QW Auto Shut Off Valve ASO for Reverse Osmosis Systems 1/4" QC White

The Hydronix ASV-14QW is an automatic shut-off valve (ASO) designed for residential Reverse Osmosis (RO) systems.
This valve is a standard replacement part compatible with most RO units on the market, including brands like Watts, Flowmax, Goldline, and Apec.
An Automatic Shut-Off (ASO) valve for reverse osmosis (RO) systems stops the water supply to the membrane once the storage tank is full and pressurized, typically at 65% of the incoming line pressure. It prevents constant waste water flow, acting as a pressure-sensitive diaphragm switch, saving water and extending filter life. Most units are 1/4" quick-connect compatible.
Auto Shut Off Valve Installation Tips

• These ASO Valves are compatible with most Reverse Osmosis systems on the market.
• Port Identification: Most ASO valves have a "high pressure" side (incoming water) and a "low pressure" side (tank/pure water). The side with screws typically indicates the permeate (pure water) side.
• One-at-a-Time: When replacing a valve, disconnect and reconnect the tubes one by one to ensure you don't mix up the four connection points.
• The low pressure from the membrane gets connected to the in of the low pressure side, the low pressure out goes into the tank.
• Check Valve Requirement: An ASO valve must be used in conjunction with a check valve

Common Issues & Troubleshooting
If your RO system is constantly running to the drain, the ASO valve or the check valve may be faulty.

• Testing the Valve: Close the tank's ball valve to simulate a full tank. If the drain water does not stop within 3–5 minutes, one of these valves is likely failing.
• Check Valve vs. ASO: If water continues to flow even when the main supply is shut off (but the tank is open), the check valve is leaking water back from the tank. If flow only stops when the main supply is off, the ASO valve is usually the culprit.
• Clogs: Internal diaphragms can become "gummed up" or plugged over time, which may require cleaning or complete replacement.
• Scroll for available options and Specs