In this section of Home Improvement, I Explain all about Doorbell Repair: Repairing Doorbells and How to Fix Doorbell Problem including doorbell transformer problem, what to do when doorbell hums but doesn’t ring, what to do when doorbell makes no sound and other problems and troubleshooting.

Before I proceed, I must inform you that repairing a doorbell is quite easy. The buttons, buzzers, and transformers used in doorbells are relatively inexpensive and replacing these faulty doorbell parts and components is better than trying to repair them.

Let us now learn and understand how to repair and fix some common problems with doorbells.

A doorbell transformer is normally located inside the bell or chimes enclosure. But sometimes it may be located elsewhere and finding it may get difficult for you.

To find the location of the transformer, trace the wires running from the doorbell.

How to check if the transformer is working or not?

Normally the proper voltage rating is stamped on the transformer or the doorbell and is also mentioned in the user manual.

To check the transformer:

1) Adjust a volt-ohm meter's scale to 25 VAC.

2) Attach the two probes to the two screws that connect the small-gauge doorbell wires to the transformer.

3) Measure and compare the reading to the doorbell’s voltage requirements as mentioned on the transformer or in the user manual. If the reading is too low or exceeds 16 volts, the transformer is probably faulty. Shut off the power and replace the transformer with a new one from home electronics store.

If your doorbell is relentlessly buzzing or humming, most probably the push button is stuck in the contact position. If the button gets stuck for a long time and the doorbell keeps buzzing and humming, the electromagnet may burn out and the bell unit won't work. You need to repair or replace the button immediately before the bell unit gets damaged.

When the button is pushed and the transformer hums but the bell doesn’t ring, here is what you can do:

a) Check the bell and the wiring and make sure the wires are connected to the terminals in the bell unit. Clean the contacts with fine sandpaper or electrical contact cleaner if required.

b) Check if there is any break in the doorbell wiring. If you find any break in the wiring, strip the insulation from the wire ends and splice them with a short piece of matching wire.

c) You may also have to check the piston. The piston may be worn and jammed inside its sleeve. If this is the case, you may have to replace the electromagnetic/piston component or even the entire bell unit.

Repairing a doorbell that makes no sound is easy.

When you push the doorbell button and do not hear and bell or sound, most possibly electricity is not being delivered through the system. Here is what you can do:

1) Check is a circuit breaker has tripped.

2) Turn off the power to the circuit and check the transformer (explained above).

3) Be sure all wires are connected securely at transformer, bell, and button.

4) Check the button which is most likely component to fail in any doorbell system. To check the button, remove the screws from the button and gently pull it out. Make sure the two wires are connected securely to the screw terminals. Then touch a screwdriver blade across both terminals or remove the two wires and touch them together. This will help you know if current is passing through these wires or not. When you touch both the wires and the bell rings, remove the wires, and clean corrosion from the button's contacts and wire ends with fine sandpaper or any electrical contact cleaner. Now reconnect the wires. If the button still does not work, you may have to replace the button by getting it from any home appliance or home electronics store. They are also available at hardware stores.

Read More on Doorbells

>>> Doorbells: How Doorbell Works

>>> Installing Doorbells and Door Chimes