The two valve controls on almost all kitchen faucets deliver a mix of hot and cold water. Adjusting the valves, whether they operate with two control knobs or a single-lever faucet control, lets you regulate water temperature and rate of flow. You can also make other adjustments to the plumbing that will alter water volume and the ratio of hot to cold flowing into your sink. These changes take only a few minutes.
Turn off the water at the faucet over the sink.
Open the cabinet doors below the sink to locate the two water-control valves inside against the back wall. The knob on the left controls cold water. The knob on the right adjusts hot water.
Turn the right knob under the sink clockwise to increase hot-water volume to the maximum level, which will be as far as the knob will turn. Use pliers or a wrench if turning the knob proves difficult. Twist the knob counterclockwise to reduce hot-water volume through the sink faucet.
Adjust the left knob to change the amount of cold water flowing through the faucet with the hot water. If the knob is turned counterclockwise until the valve is shut off, only hot water will flow through the faucet.
Adjust the temperature control on your hot-water tank to increase or decrease the temperature of the hot water. The temperature control is typically located on the side of the tank. On some tanks, you must remove the curved metal plate on the tank's side near the top with a screwdriver to expose the temperature control underneath. You can also turn the right control knob on top of the tank clockwise to increase hot water volume flowing through the plumbing system. However, this will affect all faucets in the house, not just the kitchen sink.