How do door chimes work and how do you repair them when they stop working?

Answer 1

This is accurate for old style electromechanical door chimes. I believe the procedures will work with electronic chimes, but I have no experience with them so it may not. Your door chime system consists of three parts: * A step down transformer. Ususally 120VAC->24VAC and commonly mounted near the breaker panel. This powers the system. * A button by the door. * The chime unit. These three parts are wires in series. When the button is pushed it completes the circuit from the transformer to the chime. The energy draws a plunger into a solenoid. The inerta of the plunger draws it past the energized resting position, striking a chime to make the "ding". The plunger then comes to rest, held in the solenoid. When the button is released a spring pushed the plunger back out. Again, inerta oushed the plunger past its true resting position, striking the chime to make the "dong". Note: You will need a AC voltmeter for this. * Locate the transformer. You should see 24VAC (check the transformer rating to verify this) across the output terminals. If you don't see this the transformer is the problem. Check that it is powered. If the transformer has power but us not putting out an output voltage the transfoemer has failed. * Take the cover off your chime. You should see three terminals: a common, a front door chime terminal, and a back door chime terminal. Check the voltage across the front door terminal and common. It should be 0V. Have a helper push the door chime button. The voltage should go to the voltage you read across the transformer. If these measurements are as expected the chime has failed. * Pull the button out. You should see the transformer voltage across the terminals when the button is not depressed. When the button is depressed the voltage should be 0V. If you short the terminals the chime should sound. If you can sound the chime by shorting the wires the button has failed. * If you think the chime is bad, disconnect the wire from the front door terminal and connect it to the rear door terminal. There are two solenoids in the unit, so this is a quick test case. The chime should now sound as normal, but only sound one tone. If so, the front door soleniod is bad. You will have to replace the whole chime. If not, there is a problem somewhere else. * If you can't track down the problem above, completely disconnect the wiring from the transformer and short the two wires together. Disconnect the two wires from the chime and short them together. Disconnect the switch and measure the continuity between them. If you see more than a few ohms, you have a break in the wire. Have you done anything that would cut a wire or cause it to break lately? * Somewhere there is a splice, usually at one of the three components, as you need two runs of two cinductor wire to connect the 3 components. Find this and check it. You can also disconnect it and test the two runs independently.