Step 1: Confirm You Need Instant Hot, Not Filtered Cold
Kohler dispenser products deliver hot water only -- the K-6665 series has no chilling or filtration function. If your goal is clean drinking water at room temperature or chilled, you need a separate filtered pitcher, countertop cooler, or under-sink RO system. Kohler instant hot dispensers are purpose-built for boiling-range water at the kitchen sink for tea, instant noodles, oatmeal, and similar applications.
Step 2: Measure Under-Sink Clearance for the Tank
The K-6665 tank assembly is 12.75 inches tall and 7.5 inches in diameter. It requires a minimum of 14 inches of vertical clearance under the sink cabinet, plus space for the cold-water supply line and power cord. If your under-sink cabinet is shallow or already occupied by a garbage disposal, measure before ordering. The power supply must reach a GFCI outlet -- Kohler recommends a dedicated 120V 15A circuit for the 1500W element.
Step 3: Match the Faucet Finish to Your Kitchen Suite
Kohler offers the K-6665 dispenser faucet in Vibrant Stainless (VS), Brushed Vibrant (BV), Oil-Rubbed Bronze (2BZ), and Polished Chrome (CP). If your main kitchen faucet is a Kohler Simplice or Kohler Arbor in Vibrant Stainless, the VS dispenser will match. Mixing Kohler finish codes is discouraged because VS and CP have different light-reflectance profiles that look mismatched on the same sink deck.
Step 4: Evaluate Single vs. Dual Tank for Your Usage Volume
One K-6665 tank delivers approximately 60 cups per hour. A household of 1-4 people making 2-3 cups of tea and occasional instant meals will never outpace a single tank. Catering prep kitchens or home offices with 6-plus users may benefit from adding a Kohler Singletank (K-72218) as a secondary storage vessel piped in parallel -- this doubles effective hot water capacity without adding a second faucet hole.
Step 5: Budget for Installation Labor
Kohler K-6665 installation requires drilling a 1.375-inch hole in the sink deck for the faucet, connecting a 3/8-inch compression cold-water supply line to the tank inlet, routing the power cord to a GFCI outlet, and setting the thermostat. Total labor is 1-2 hours for an experienced plumber. DIY installation is feasible if you are comfortable with under-sink compression fittings and electrical connections -- Kohler provides a detailed instruction sheet (document 1000005455) in every box.