In this video, This Old House plumbing and heating expert Richard Trethewey delivers clean, filtered water right at the kitchen sink.
1. Take the escutcheon plate from the water filter and set it on the sink deck where you'd like to install the filter's faucet. Mark the center hole of the escutcheon onto the sink deck with a pencil.
2. Drill a ⅜-inch-diameter pilot hole through the sink deck on the escutcheon's center mark.
3. Install a slug cutter in the pilot hole. Then, use a ratcheting box-end wrench to tighten the nut until the cutter punches a hole in the sink deck. Remove the slug cutter.
4. Set the faucet into the hole in the sink deck, and secure it by using a basin wrench to tighten the retaining nut from below.
5. Close the cold-water shut-off valve under the sink. Disconnect the cold-water supply line from the kitchen sink faucet.
6. Thread the L-shaped fitting that comes with the water filter into the kitchen sink faucet. Then, tighten the cold-water supply line to the bottom of the L-shaped fitting.
7. Screw the filter's upper housing and hanger bracket to the inside of the sink cabinet.
8. Insert the filter cartridge into the bottom of the housing and give it a quarter turn to lock it in place.
9. Push the inlet and outlet water-supply tubes to the top of the housing.
10. Open the cold-water shut-off valve and test the operation of the water-filter faucet.