The auto shut-off valve and flow restrictor combination regulates the flow and use of water in the RO system, serving three very important functions - it holds the water in the RO membrane so that it is purified fully, it reduces water waste, and it prolongs system life. Due to our advanced flow restriction configuration only 4-5 gallons of brine water are made per gallon of drinking water depending on water conditions and pressure, compared to the common 8-9 gallons of brine water produced per gallon of drinking water on competitors' RO systems. The automatic shutoff consists of 2 diaphragms and a plunger. The plunger moves up or down in the housing based upon pressure differential between the incoming water pressure, and the back pressure from the reserve tank.

The lower diaphragm pushes the plunger up allowing feed water to flow through the inlet/outlet port until the storage area pressure exceeds one half the inlet pressure. At this point, the storage area pressure on the upper diaphragm is great enough to push the plunger down stopping the flow of feed water. Flow will not start again until the storage area pressure drops because of water withdrawal at the faucet.

Furthermore without the auto shut-off valve, water would rush through the system wearing down components and sending purified water down the drain after the reserve tank is filled. This is one reason why most competitors rate their membrane life to only 1-2 years. With the Home Master you can reasonably expect your membrane to last 3-5 years.

Home Master Systems with the permeate pump upgrade do not require an automatic shut off valve, as the permeate pump will function in this capacity.