Things You'll Need
Door buzzer assembly with built-in transformer
Power drill with appropriate-sized bit (check screws in buzzer assembly to identify proper size)
Today, it's common to find many doors that have a doorbell, door chime or a door buzzer. All three require a similar installation process. The task takes just an hour or two and is a simple process. You may choose to replace a door bell transformer or install the whole door buzzer assembly at once. Whether you want to replace your old, defective door bell or simply change an outdated device, installation is the same.
Switch off the power to the portion of your house where the door buzzer will be located. Note that your door buzzer assembly has two parts: a doorbell switch for pressing and a chime unit with a built-in transformer.
Decide where you want to mount the chime unit of your door buzzer. Note that the location typically has to be near the door. Be sure to mount the chime unit at a height that you will be able to reach if ever you need to repair it.
Mark the place where you are going to install the doorbell switch on the wall with a pencil. Hold the door buzzer unit to the wall and mark the buzzer's screw hole locations. The height of the buzzer should be at least 4 feet from the ground or around the height of the door knob.
Drill the wall to make holes for the mounting screws. Remember to always select a drill tip that is a size smaller than the screw. Use a power drill to make the holes in the pre-marked locations. Be sure to hold the drill straight and steady.
Attach the door buzzer to the wall, firmly and securely. Use the screws from the installation kit and tighten them as much as you can by turning them clockwise with a screwdriver. At this point you will only attach the back side of the device, since you still need to plug the wires.
Connect the wires from the door buzzer. Connect the wire from the door switch to the terminal screw of the power source or transformer, then connect the other wire of the door switch to the chime unit. Now connect the wire from the door switch to the other terminal screw of the transformer. Every instruction manual has a diagram that helps you connect the harness properly, so make sure to follow the instructions for your particular model.
Put the cover of the doorbell switch in place. The cover usually clicks onto the switch through the use of plastic clips along its sides.
Restore power to the door buzzer.
Test your new door buzzer and adjust the volume control by turning the volume knob inside the chime unit.
Consider different sounds when purchasing a door buzzer. Some of the models are too loud, so make sure to check whether your model can be adjusted to the volume level you prefer.
Use great caution when working with power tools and wear personal protective gear during the whole process.
If you are not sure how to correctly plug the wiring, even with the help of a diagram from the instruction manual, consult a professional.