Inspect the wiring
1 of 1
Photo 1: Wire repair
Inspect the wires for damage. Repair breaks with twist-on connectors. Splice in
new wire to add length and allow for connections.
A complete inspection of doorbell wiring
is usually impossible, since most of the
wire is hidden inside walls. But some wire
is visible in every home, and that’s usually
the stuff that gets jolted loose or broken.
Inspection takes only a minute. You may
find a few inches of wire exposed near the
transformer or several
yards running through an unfinished
basement. Doorbell cable consists of three
or more thin wires inside a plastic sheath
(Photo 1). Look for areas where the
sheath is damaged and also for pinched or
badly kinked sections. Sometimes the only
way to tell for certain whether wires inside
the sheath are damaged is to carefully slice
open the sheath with a utility knife. If you
find broken wire, strip the broken ends
and rejoin them with wire connectors.
Often there’s not enough slack in the wire
to allow for new connections. In that case,
add a short section of wire between the
broken ends (Photo 1). A spool of 18-gauge wire is available at hardware
stores and home centers. The color of the wire doesn’t matter.
If you have doorbell buttons
at the front and back of your
house and one of them works,
you can be sure that the non-working
button or the wiring
connected to it is bad.
Bypass the button
1 of 1
Photo 2: Doorbell button
Remove the doorbell button and disconnect
one wire from its terminal
and touch it to the other terminal. If the
chime rings, it's the button that's bad.
If you don't find a broken wire, remove
the doorbell button by unscrewing it or
prying it out of its hole with a putty knife.
If the bell rings when you bypass the button
(Photo 2), replace the button.
Buttons are available at home centers and
hardware stores. If the
bell doesn't ring, reconnect and reinstall
Check the chime
1 of 2
Photo 3: Chime
Remove the chime cover and check for voltage while a helper pushes the button.
2 of 2
If the tester lights up but the armatures don't move,
clean them with rubbing alcohol.
When a doorbell works properly, small
armature rods inside the chime strike
metal bars or tubes to create sound.
Sometimes the armature sticks or you
have a loose wire. To find out, remove the
chime cover. Many covers simply lift off.
Others are fastened with latches or screws.
With the cover off, make sure the wires are
firmly connected to the screw terminals.
You’ll need a test light to check the
chime itself. Be sure to get a low-voltage tester.
Standard voltage testers look just like the
one shown here, but they won’t detect low
voltage. Touch the common terminal
(labeled “com” or “trans”) with one of the
With the other probe, touch the front
or back door terminal while a helper
pushes the button (Photo 3). If the tester
lights up, you know the chime is receiving
power and there’s something wrong with
the chime itself. Sometimes the armatures
are too grimy to move. Clean them with
rubbing alcohol and move them with your
finger. Then try the button
again. If the chime still doesn’t ring,
replace it. Label the wires as you remove
the old chime and connect them identically
to the new chime. Chimes start are sold at home centers and hardware
stores. If the tester doesn’t light up when
your helper pushes the button, the chime
isn’t receiving power because of a broken switch, transformer or wiring.
Test the transformer
1 of 1
Photo 4: Transformer
Test the transformer by touching the screw terminals with a low-voltage test
light. If the tester doesn't light up, replace the transformer.
The transformer, which converts standard
household voltage to low voltage, is the
least likely component to cause doorbell
trouble. It can be located anywhere in
your home, but you’re most likely to find
it on a metal junction box near your heating/
cooling system or mounted on the
outside of your main electrical panel.
First, make sure the bell wires are securely
connected to the transformer terminals.
Then test the transformer (Photo 4). If
the transformer is mounted on a junction
box, you can replace it yourself. Be
sure to turn off the power to the circuit at
the main panel and then make sure it’s off
by using a non-contact voltage detector
before disconnecting wires. If the transformer
is mounted on the main panel, we
recommend that you hire a licensed electrician
to open the panel and replace it.
When all else fails, go wireless
If none these tests exposes the problem,
you can bet that a wire is broken somewhere
inside a wall. You might be able to
locate and repair the break without tearing
into walls, but the odds are against
you. So the best solution is a wireless
system. With a
wireless doorbell, the button sends a radio
signal that triggers the chime. On the downside, an electronic chime may not
create the harmonious ring of metal, and
both of its components require new batteries