Do it yourself: how to install an extra chime for a louder doorbell

You don’t need to be an electrical engineer to doctor your doorbell.

Photo Credit: Liv Friis Larsen
By Nicole LeBoeuf-Little

It can be hard to hear the doorbell in all areas of even a small house, let alone a multi-story home with basement and backyard. You might feel obliged to hover in the vicinity of the chime when expecting visitors, or just leave the front door unlocked and instruct your guests to come on in and holler up the stairs. But you can better solve this problem by installing additional chimes where the original one fails to reach.

Your home probably came equipped with a standard low-voltage two-wire doorbell installation. This system usually comprises a button, a bell or buzzer, and a transformer. Each is connected to the other two to form a continuous circuit. A push of the button shorts the circuit, causing the bell to ring. Meanwhile, the transformer adapts regular household current to the low-voltage requirements of the doorbell.

Wiring a new chime into this system may necessitate replacing your transformer, as it will now need to supply enough current for two noise-makers instead of one. Check the requirements of your chimes against the transformer’s specifications. You will probably need to replace your 10-watt model with a 30-watt unit.

Another factor that my require a transformer upgrade is wire length. If your new chime’s location requires a really excessive length of wire, you may experience a drop in voltage. Most chimes require a 16 volt system; upgrading to a 24-volt transformer should ensure that the voltage drop won’t cripple your chime. But unless you have an enormously long house, or you’re trying to install a chime in the tree house in the neighbor’s back yard, wire length probably won’t be a factor.

The transformer is usually installed near or on your household circuit breaker box. But before you try to replace or even touch the wiring on your transformer, it’s extremely important that you turn off the appropriate circuit breaker! The low doorbell current is harmless enough, but the other side of that transformer is plugged into your house current–and 110 volts can deliver a nasty shock. Once you think you’ve found the right circuit breaker, use a circuit tester to ensure that there really is no current.

Having replaced your transformer, locate the screw terminal on the low-voltage side whose wire leads to the existing door chime. You’ll attach the new chime’s wire to this terminal, too. Use solid bell wire, 18 or 20 gauge, not stranded copper. Next, go look at the doorbell button. Again, determine which of its terminals leads to the existing chime, and add to it a wire leading to the new chime.

Now all you need to do is fish the new wires through the walls to the location of your new chime. Attach the wires to the chime’s terminals, switch the circuit breaker back on, and give that doorbell button a push. Ding-dong!

But maybe all this fiddling about with wires and circuit breakers isn’t your cup of tea. In that case, modern wireless technology has a couple solutions for you, depending on whether you want to keep the existing doorbell circuit or replace it altogether.

If you don’t mind replacing batteries from time to time, you might want to purchase a replacement doorbell system which consists of a battery-operated doorbell and transmitter unit at one end and a remote chimes on the other. The doorbell transmits a radio signal which tells the chimes to sound. The chimes can be battery operated, like the button, or they can plug into a regular household wall outlet. These systems are infinitely extendable; any number of chimes within range will sound when the button gets pressed.

To avoid the issue of battery replacement, you can expand your existing low-voltage doorbell system with a wireless chime extender. Like the entirely wireless system, this works by means of a radio transmitter and plug-in remote chimes, but the transmitter installs directly onto the screw terminals of your doorbell button. Typically the transmitter doesn’t require much power, so you needn’t upgrade the transformer or indeed touch it at all. Nevertheless, it’s a good idea to shut off the circuit breaker before exposing and manipulating the button’s screw terminals.