If RO Makes Noise- – RO-45

　　Should RO Emit Noises: – RO-45

　　Dealing with Air Trapped in the Check Valve – If your RO system emits a whining or humming noise, it usually points to air being trapped inside the "Check Valve" during the installation. Our aim is to remove the air from the Check Valve, which is found on the left side of the Membrane Housing (see Fig. Step2) and is housed within an L-shaped plastic bracket, connected to the "Clear" line that delivers purified water from the Membrane Housing.

　　To eliminate the air bubbles, follow these steps (see accompanying images for guidance):

　　Step 1: Close the Tank valve.
Step 2: Tilt the RO system to the right, supporting the 3rd filter housing to keep it tilted. This helps to release the air bubbles from the Check Valve.
Step 3: Turn on the RO faucet, letting pure water flow out for around 1 minute. This pushes the air directly to the faucet, bypassing the tank.
Step 4: Stop the water flow from the faucet, then wait for about 10 seconds. Repeat Step 3, 3-4 times, or until the noise stops.

　　After the noise has stopped, reopen the Tank valve and use the RO system as usual.

　　If the noise returns, try the above steps 2-3 times again. It may take several tries to remove all the air from the system.

　　If the noise continues after a few days, it could indicate either air in the water source or the Check Valve vibrating in sync with the water pressure and pipes, causing the noise. Installing a new Check Valve should resolve this problem.