Fixing a doorbell, in most cases, is a relatively quick, simple and inexpensive job that you can complete on your own. If your doorbell does not ring, there could be four possible problems with it. It could be the chime, the transformer, the button, or the wiring connecting them all. You can track the culprit easily and make the fix.
You do not have to worry about working with electricity as a majority of the doorbell circuitry is usually low-voltage and will not give you any shocks in case you make contact with the wires. A transformer considerably reduces the typical 120-volts carried by many electrical circuits to just ten to sixteen volts needed to operate a doorbell.
We have a useful how-to article to walk you through the process of repairing an old door.
Inspect the Wiring
It is often impractical to perform a complete and thorough inspection of doorbell wiring, which is because the majority of the wire runs inside walls. However, some of the wirings are usually visible in every house, and these are the bits that often get jolted loose or damaged.
Wire inspection is not very time consuming and usually takes only a couple of minutes. You may easily notice a few inches of doorbell wire exposed around the transformer or a couple of yards running through your incomplete basement. Doorbell cables consist of 3 or more wires wrapped in a plastic sheath. These wires are very thin. Look for those sections where the sheath is broken or damaged and for areas that are badly kinked or pinched. At times, there is only one way to determine, with certainty, if wires in the sheath are impaired, and it involves carefully slicing open the sheath using a utility knife.
In case you find damaged wiring, strip the damaged ends carefully and rejoin these ends using wire connectors. In many cases, there will not be sufficient slack in the doorbell wire for you to make new connections. In this situation, you can make new connections by adding a short piece of wire between the damaged ends. Spools of 18-gauge wire are easily available at most home centers and hardware stores. You do not need to worry about the color when buying the wire as it does not matter.
Test the Button
In case you are not able to locate a broken or damaged wire, it is time to test the doorbell button. To remove the button, unscrew it or pry it out of the hole using a putty knife. Loosen all the screws at the back of the doorbell button then disconnect the wiring. Then bring the two wires in contact with each other. If the bell chimes, the doorbell button is not functioning and will need to be replaced. You can find buttons at hardware stores and home centers.
Check the Chime
When your doorbell is working adequately, a tiny armature in the chime rods strikes the metal tubes or bars to produce sound. At times, this armature sticks or a wire comes loose. You can find out if this is the case by removing the cover of your chime. Most covers are easy to lift. However, some comprise of screws or latches. After removing the cover, inspect the wires and ensure they are firmly connected to their screw terminals.
You will have to use a test light for checking the chime. Make sure that you work with a low-voltage tester when checking the chime. Regular voltage testers may not be effective in this situation as they will not be able to detect the low voltage of the doorbell. Using one tester probe touch the common terminal. This terminal is typically labeled trans or com. With another probe, touch either the back or front door terminal while another person presses the button. If your tester glows, it indicates that your chime is receiving the requisite power which suggests that something is wrong with your chime.
On numerous occasions, the armatures in the chime are too encrusted or grimy to move. You should clean them thoroughly by rubbing alcohol then move them gently with your fingers. When you are done, push the button once again. In case the chime fails to ring, you will need to replace it. Label all the wires carefully when you remove your old chime so that you can easily identically reconnect them to your new chime. Chimes are available at hardware stores and home centers. In case your tester does not light up when the button is pushed, it suggests your chime is not receiving sufficient power due to a broken transformer, switch or wiring.
Test the Transformer
The transformer is often the least likely culprit that can lead to doorbell trouble. Its job is to convert normal household voltage to very low voltage. The transformer may be located anywhere in the house, but you will likely find it in a metallic junction box around your cooling/heating system, or it could be mounted on your electrical panel. You should first ensure the doorbell wires are firmly connected to the terminals of the transformer.
Now test your transformer. If it is mounted on the junction box, it is safe to replace it on your own. Make sure you turn off the power supply to the main circuit at the panel and ensure it is off with a non-contact detector before you disconnect the wires. In contrast, if your transformer is on the main electrical panel, it is recommended that you engage an electrician to open and replace the panel.
Nearly 90% of the time, according to experts, when a doorbell malfunctions, it is due to faults with the button as it is located outside and wears out quickly because of constant use or weather. However, it is also likely that the transformer, chime or the wiring of the doorbell may stop working. If all the above tests fail to expose the issue, it is likely that a wire inside the wall is damaged or broken. Although you may be able to pinpoint and fix the break or damage without going to the trouble of tearing into your walls, the odds are often stacked against you.
Therefore, in this case, the ideal solution is to go for a wireless doorbell. In a wireless system, the doorbell button transmits a radio signal to trigger the chime. This simplifies and quickens the installation process, and you will just need to replace the batteries occasionally. Also, it frees you from the hassle of rewiring.