Remove the temperature range label on the thermostatic mixing valve to access the temperature controls.
Fit a 3/16-inch Allen wrench into the screw.
Turn the wrench counterclockwise to raise the temperature, or clockwise to lower the temperature.
Run hot water out of any faucet in your home. Use a thermometer to measure the temperature. Readjust the thermostatic mixing valve as needed to correct the temperature.
Locate the hand wheel on top of the main valve body.
Use a screwdriver to loosen the screw on top of the hand wheel. Don't remove the screw entirely.
Lift the hand wheel slightly, but do not attempt to remove it. Lifting it allows you to adjust the temperature.
Turn the hand wheel counterclockwise to reduce the temperature. Turn the wheel clockwise to increase the temperature.
Press the hand wheel down gently to lock in the temperature setting. Tighten the screw.
Measure the hot water temperature from any faucet in your home. Readjust the temperature setting as needed.