Clean out the area under the sink to make room for the tank.
Next, shut off the water at the water heater.
Turn off the power at the breaker. If your water heater is gas, turn the control to the 'Pilot' setting.
Drain the water lines. Turn on the faucet at the sink where you are working, as well as an outside faucet.
Note: If there isn't an existing hole in the sink, a hole will need to be cut for the water dispenser.
Make a dimple into the sink where the dispenser will be placed, using a drill set and hammer.
Using acordless drill and a stainless steel bit, drill a 3/4" hole into the sink (Image 1).
A slug buster can also be used to cut the hole. To do so, take the cutting wheal off the slug buster (Image 2). Place the slug buster into the hole, then reattach the cutting wheel underneath. Hand tighten the nut on the top side of the slug buster, then use a wrench to continue tightening until you hear a 'pop' (Image 3). Remove the slug buster.
Use an emery cloth to smooth the edges
Safety Note: Always wear safety glasses when cutting metal.
Note: If the sink is cast iron, make the cut into the countertop near the sink using a hole-saw (Image 4).
Place the seal ring to the underside of the dispenser (Image 1).
Place the dispenser into the sink.
Attach the mounting ring from the underside of the dispenser over the threaded rod (Image 2).
Add the hex nut, then tighten to secure.
Loosen the compression nut at the cold water stop under the sink, then remove the line.
Install a double compression stop to the water line, then reattach the lines to the sink.
Position the tank close to the plumbing and the electrical outlet. While holding the tank in place, draw a line on the wall to mark the top of the tank.
Attach the mounting bracket 1" from the line using a drill bit and 1" wood screws. Hang the tank on the bracket.
Push the blue tubing into the quick-connect fitting on the tank. Slip the clear vinyl tube over the fitting in the middle. Connect the larger tube over the last barbed fitting.
Attach the mounting bracket near the tank, then attach the filter.
Connect the 3/8" tubing from the outlet side of the filter to the 3/8" Y fitting.
Add the clear vent line to the filter (Image 1).
Insert both copper lines from the dispenser to the Y fitting (Image 2).
Attach a compression nut over the 3/8" tubing. Then, attach to the double compression stop installed at the existing water line and tighten.
Turn the water back on at the water heater.
Open the water stops under the sink, then check for leaks.
Open the cold water faucet at the new dispenser to wash out the filter. Turn off the cold water faucet, then open the hot water faucet until water begins to flow.
Plug in the tank.