Remove Old Thermostat

• 1). Locate the position of the old thermostat. The new Lux TX1500 will replace the old thermostat. Turn off the electricity to all heating and cooling components in the house. Do not turn on the electricity until the new thermostat has been installed.
  
  
• 2). Remove the cover and front portion of the old thermostat to reveal all of the wiring connections. Write the letters that are printed near each used wire terminal, as well as the color of the wire that is connected to it. Using the provided labels, connect a label to each of the wires. Make sure that the letter on the label matched the marking on the existing thermostat.
  
  
• 3). Remove each wire from the old thermostat one at a time. Make sure that the wire does not fall back inside of the wall, and that the wire ends do not touch each other or the thermostat. Using the #1 Phillips screwdriver, loosen all of the screws on the old thermostat and remove it from the wall.
  
  

Install New Thermostat

• 1). Strip the insulation from the wall (using the wire stripper / cutter), leaving 3/8 inch (9.5 mm) bare wire ends. Clean off any corrosion from the wires. Fill the wall opening with non-combustible insulation. This prevents drafts from affecting the thermostat temperature.
  
  
• 2). Remove the body from the new thermostat's base by pressing the thumb latch at the bottom center portion of the unit. Swing the body away from the rest of the thermostat. Hold the base against the wall. Route the wires through the hole located below the terminal block. Attach the base to the wall using the two screws provided and the Phillips screwdriver.
  
  
• 3). Trap the end of the wires between the black clamps and the brass terminals on the thermostat. Tighten all of the electrical terminal screws by tightening them with the screwdriver. Tighten any unused terminals as well.
  
  
• 4). Locate the battery compartment (found at the rear of the thermostat, on the circuit board). Install two AA size alkaline batteries (either Energizer or DURACELL brand) into the compartment. Ensure that the batteries are installed correctly using the polarity markings on the compartment.
  
  
• 5). Use the new Lux TX1500 thermostat. Use the temperature buttons at the top of the thermostat to raise or decrease the temperature. Flip the Temperature Mode Switch on the bottom right side of the device to switch between "Heat," "Cool," or "Off." View the LCD display to receive information about the room temperature, battery levels and other critical information.