How to Repair a Broken Doorbell

By Mark J. Donovan

A doorbell is an appliance in our home that we tend to forget about, until it no longer works.  Fortunately repairing a broken doorbell is a fairly straightforward do it yourself project. All that is required are a few basic homeowner tools, and possibly one or two replacement parts that you can normally find at any home improvement store.   Start with the Doorbell Button   If the doorbell is no longer ringing when you push the button, check the button itself. Due to the fact that doorbells are exposed to the weather they have the tendency to breakdown over time.

 

Simply remove the doorbell button cover and check to make sure the wires are still properly attached. If they are, remove the wires and touch them together. Alternatively you can also just short the two contacts (where the wires connect) together using a screwdriver.

 

Note: typically the wires with doorbell switches are low voltage so there is limited danger of shock, however to be careful do not personally touch the bare wires, or the metal portion of the screwdriver when shorting out the contacts. 

 

 

Check the Doorbell Transformer

 

If the doorbell button is not the source of your broken doorbell, then you should next check the doorbell transformer.

 

A doorbell transformer reduces your home’s 120V electricity down to 10-16V. This low voltage supply then feeds the doorbell chimes. The doorbell transformer normally sits near the main circuit panel box or junction box.

 

First inspect the low voltage wires that connect to it. These are the wires that feed the doorbell chimes. If there are loose wires or connections tighten them with a screwdriver.

 

 

If the wires look tightly secured, use a multimeter set to 50V AC to measure the voltage across the low voltage terminals. If there is no voltage indicated on the digital volt meter then you need to replace the doorbell transformer. Likewise if there is a low voltage (below 6V) or a high voltage (above 16V) on the transformer the transformer needs to be replaced. Again, you can buy a replacement doorbell transformer at most home improvement stores.

 

Warning - To replace a doorbell transformer; make sure you first turn off AC power to it at the main circuit panel, as there is the risk of life threatening shock.

 

To replace the doorbell transformer, turn power off at the main circuit panel, then label the doorbell transformer wires with tape, marking their location to where they were wired.

 

Next remove the wires, and swap out the bad transformer.

 

Connect the wires onto the new transformer, per the markings on your tape. Typically the 120V black wire coming from the circuit panel is attached to the black wire coming from the high voltage side of the transform. Similarly, the 120V white wire coming from the circuit panel is attached to the white wire coming from the high voltage side of the transformer. The green wire associated with the transformer attaches to the bare ground copper wire. The low voltage chime wires then attach to the low voltage contacts on the transformer.

 

Check Doorbell Chimes Wiring

 

If the doorbell button and transformer seem to be in working order, then it is time to look at the doorbell chimes wiring.

 

Remove the doorbell chimes cover and examine the chimes wiring. Again, check for loose or broken wires. If they are broken reattach them and if they are loose, tighten the wiring and secure them with electrical tape. Again use a multimeter set at 50V AC to measure the voltage across the two wires coming in from the transformer. If the voltage is between 6 and 16 Volts, then the doorbell problem lies with the doorbell chimes themselves. If this is the case replace the chimes.

 

When replacing the chimes, make sure you tape and mark the wires first before removing the chimes as this will make the replacement effort much easier, and error free.

 

Following these basic steps you should be able to safely repair a broken doorbell within an hour.

 

For information on Changing a Light Switch, See HomeAdditionPlus.com's  "How to Change a Light Switch Ebook". It provides detailed, easy to understand, step-by-step instructions and pictures, on how to replace a Light Switch.