Diagnose in this order:
- Check water supply: Confirm the main feed water valve to the system is open.
- Check tank valve: The blue tank ball valve on the tank must be in the open (horizontal) position.
- Check pressure: System requires sufficient incoming water pressure to operate. Maximum operating pressure is 85 psi.
- Check auto-shutoff valve: Located on the RO head. If the storage tank is full, it shuts off flow. If the tank is empty and it's still shut, the valve may be faulty.
If that didn't work: Examine the drain saddle connection on your sink's drain pipe. If it's clogged or installed incorrectly, it can cause abnormal shutoff. Ensure the drain line (1/4" black tubing) is not kinked.
Prevention: Install the system indoors, away from direct sunlight and temperature extremes, which can damage components.