How To Replace a Doorbell

Replacing a doorbell is a task most homeowners can tackle on their own, but it isn’t always straightforward. From hunting down hidden components to navigating wiring issues, this project demands careful planning and execution. Whether you’re troubleshooting an existing system or installing a new one, this step-by-step walkthrough will help you repair or replace your doorbell so it rings like new.

Understanding Doorbell Components

A doorbell system has three main components: the doorbell button, the chime, and the transformer.

• Doorbell button: This is mounted outside your front door. Visitors press it to activate the chime.
• Chime: This is the box inside your home that produces the sound when someone presses the doorbell button.
• Transformer: This is a small device that converts your home’s 120-volt (V) power to the lower voltage required by the doorbell system (typically 16 V).

Your doorbell system should have at least two wires: one that connects the button to the chime and one that connects the chime to the transformer. If there are three wires, one is connected to the button, one to the transformer, and the third is a “common” wire that may be used for additional features like a lighted button.

When someone presses the doorbell button, a low-voltage electrical signal travels along the wire that connects the button to the chime box. This triggers the internal mechanism that creates the sound. A wire running from the transformer to the chime provides the power needed for the doorbell to operate.

Assessing Your Existing Doorbell System

Before you start the replacement process, check if the doorbell button is still in place and functional. If your existing doorbell doesn’t work, some components could be missing—which was the case for the homeowner in the video. A previous owner had removed the chime and transformer at some point, leaving behind only a defunct button and a bit of wiring.

In most cases, the chime and transformer are relatively easy to find. The transformer is usually found near the electrical panel, in a closet close to the front door, or mounted to a joist in the basement. The chime is typically installed above the front door or in a central hallway.

Missing components make the project a bit trickier than a simple doorbell fix or replacement. Eastman used a toner to trace the wiring from the broken button up the wall to determine where the chime used to be—but in the end, he had to completely replace the wiring. Depending on what’s missing and the condition of what’s left, you may want to call in a professional to fix your doorbell.

Tools and Materials Needed To Replace a Doorbell

To replace your doorbell, you’ll need the following tools:

You’ll also need the following materials:

• Doorbell wiring
• Electrical tape
• Fish tape
• New chime box
• New doorbell button
• New transformer

Always turn off the power at the main breaker before working on any electrical connections. Use proper safety equipment, including gloves and safety glasses, when cutting into walls or drilling. If you’re uncomfortable working with electrical wiring, consider hiring a professional electrician.

Step-by-Step Replacement Process

Replacing a doorbell can range from simple to complex, depending on your existing system’s condition. If you have a working chime and transformer, you can skip to Step 6 and simply replace the button—unless you want to upgrade the chime, too. In that case, start at Step 4. If you are missing some components or the wiring is damaged, start at Step 1.

Step 1: Locating the Existing Wiring

Use a wire toner to trace the existing doorbell wiring inside your walls. Once you’ve identified the general location, use a magnetic stud finder to locate the studs and the cavity between them. Cut a small opening in the drywall where you plan to install the new chime. Fish out any existing wiring from the wall cavity.

Step 2: Testing the Wiring

Use an electrical meter to check that the wires you’ve found are indeed doorbell wires. Set your multimeter to measure AC voltage and choose a range higher than the typical doorbell voltage (16 V). Connect the meter probes to the pair of wires and read the results:

• 16-24 volts: This indicates that the wires are likely doorbell wires.
• 0 volts: This means the wires are not connected to a power source. It could be that the breaker is off, the transformer is faulty, or the wires are not doorbell wires.
• 120 volts: This is dangerous. It means the wires are connected to your home’s main power supply rather than a transformer. Immediately disconnect the meter probes and turn off the breaker.

Eastman demonstrates how to do this in the video, but keep in mind that working with electrical wiring can be dangerous. If you are unsure about any part of this process, or if you get unexpected meter readings, it’s best to consult a licensed electrician.

Step 3: Replacing the Wiring (If Necessary)

If the existing wiring is in poor condition, you’ll need to run new wiring from the doorbell button to the chime location. Tape the new wire onto the end of the existing wire, then carefully pull the old doorbell wire through the wall until the new wire comes through.

If the old wire breaks or won’t budge, use fish tape to guide the new wire through the wall cavity. Feed the fish tape through one side of the wall, through the stud bay, and out the other side. Attach the new wire to the hook and pull it back through, leaving 1 or 2 feet of wire on both sides of the wall.

Step 4: Installing the New Chime

Once your wiring is in place, position the new chime box on the wall, covering the hole. Use a level to ensure it’s straight, then mark the mounting hole locations on the wall.

Remove the chime and drill the mounting holes. Hammer the wall anchors into place.

Feed the wires through the chime box and attach the chime to the wall. Connect the transformer wire to the transformer terminal and the doorbell wire to the doorbell terminal. Install the chime cover.

Step 5: Replacing the Doorbell Button

Remove the old doorbell button from your home’s exterior if you haven’t already. Strip the end of each wire that runs to the doorbell, then connect the wires to the new doorbell button according to the manufacturer’s instructions.

Place the doorbell button so that it covers the hole. Use screws to mount the button to the house.

Step 6: Installing the New Transformer (If Necessary)

If you aren’t comfortable working inside your electrical panel, call an electrician to attach the wires to the new transformer. Otherwise, turn off the power to the electrical panel at the main breaker and remove the cover. 

Choose a knockout from the side of the electrical panel and remove it with wire strippers and a screwdriver. Slide the transformer’s threaded end into the panel and secure it with a locking nut. Connect the transformer to a 15-amp breaker in the panel—ideally the breaker for the original doorbell.

Finally, attach the wiring from the chime to the transformer. Close up the panel and flip the breakers back on.

Step 7: Test the New Doorbell

Once all components are installed, press the doorbell button to test the chime. Adjust the volume and sound of the chime until it is audible throughout your home. 

If the chime does not sound when you press the button, double-check all wire connections at the button, chime, and transformer. Use an electrical meter to verify that each component is functioning and receiving power. Replace any hardware that seems defective, then test again.

Troubleshooting Techniques With Doorbells

Here’s a breakdown of common doorbell problems and how to address them:

• Loose wire connections: Wires may become loose during installation or over time, disrupting the flow of electricity and preventing the doorbell from working. Make sure each wire is securely fastened to its terminal. If screws are used, tighten them snugly. If push-in terminals are used, make sure the wire is fully inserted and locked in place. Clean wires with a wire brush or sandpaper to remove any corrosion before reconnecting.
• Incorrect wiring: Wires may be connected to the wrong terminals, causing the doorbell to malfunction or not work at all. Refer to the wiring diagram that came with your doorbell or chime. It will show you the correct placement of each wire. Carefully check that each wire is connected to the corresponding terminal on the button, chime, and transformer.
• Faulty transformer or chime unit: The transformer or chime unit itself may be defective, preventing the doorbell from working even if the wiring is correct. Use a multimeter to check for voltage at the transformer output and at the chime terminals. If there’s no voltage, the component may be faulty. Buy a replacement and install it according to the manufacturer’s instructions.
• Tripped circuit breaker: If the doorbell circuit is overloaded or there’s a short circuit, the breaker may trip, cutting off power to the doorbell. Find the breaker panel and identify the breaker that controls the doorbell circuit. If the breaker is tripped (the switch will be in the “off” position or in a middle position), switch it fully off and then back on. If the breaker trips again, there may be an overload or short circuit. Consult an electrician.

Optimal Placement for Doorbell Components

Use the following guidelines to find the best locations for your doorbell button, chime, and transformer:

Doorbell Button

The doorbell button should be easily accessible and visible to visitors. Mount it at a height that is reachable by all visitors, typically between 4 and 5 feet from the ground. Make sure it is clearly marked and easily seen from the front door or entrance. Position it under an overhang or install a weatherproof button to protect it from the elements.

Chime

The chime should be placed in a location where it is audible throughout the home, such as in a central hallway or main living area. Make sure the chime is not obstructed by large furniture or thick walls that can muffle the sound. Position it high on the wall to help the sound carry throughout the house.

Transformer

The transformer should be conveniently located near the electrical panel and easily accessible. Attach it firmly to a joist or wall near the panel to prevent it from becoming loose or damaged. Keep it away from areas prone to moisture or flooding to prevent electrical hazards.