• Q. How do I connect a doorbell, doorchime, or transformer?
  • A.  Simply put, a doorbell system has a power source- a low voltage transformer.  The transformer connects to your standard power line (120 volts), and out of the transformer comes the low voltage, usually 12-16 volts.  The low voltage will use 2 wires.  One wire runs out to your doorbell button.  The other wire runs directly to the door chime (makes the sound).  Finally, a third wire needs to be run between the doorbell button and the door chime.  Picture a triangle.  Below are a few diagrams to help clear the mud:

  • Q. How do I tell if my doorbell button is broken, if the door chime is faulty, or if the power transformer and wiring might be the problem?
  • A.  Use a multi-meter to test each component.  Didn't graduate from MIT?  Don't want to call an electrician? Try disconnecting the doorbell button and then touch the two wires together briefly.  If the door chime inside works, then the button is the problem and needs to be replaced.  If touching the wires doesn't make the chime ring, you will need a multi-meter to test the wires.  If you have voltage (usually 12-16 volts, AC), then the transformer and wiring should be okay, so the door chime itself probably needs to be replaced.  If there is no voltage reading on the wires, most likely the transformer is bad, but it could be wiring as well.


  • Q. My doorbell is stuck or broken and has a constant ringing or buzzing sound, or barely makes any sound at all and then stops.
  • A. A faulty button or door chime could cause this.  However, the most common causes are that your wires are touching each other someplace (all it takes is one tiny strand of wire touching the other).  Also, the button may be 'stuck' pushed in.  Wiggle the button, or use your fingernail to make sure it's pushed out. Another less common cause may be that you replaced an existing doorbell with a new one and then noticed the problem.  If the old one worked fine before replacing the button or chime, it is likely that your old button had a diode.  The diode is often noticeable as a small capacitor, usually inside the plastic housing of the old button, but occasionally on the outside connected to one of the two wires.  If you still have the button, you should be able to take the diode out and connect it back into your doorbell wiring.  If you don't have the old button, check with the manufacturer of the door chime unit you still are using, and they will let you know what size capacitor to use.  You could also just replace the door chime unit with a new one.