How to Repair a Broken Doorbell

If your doorbell is on the fritz, you’ll never know when someone is at your door. Luckily, it doesn’t take much time or skill to diagnose and mend a broken doorbell. All you need is some basic DIY skills.

This video and guide will walk you through how to repair a broken doorbell alongside This Old House electrician Steve Krasner. We’ll also discuss the mechanics of how your doorbell works and give you tips for troubleshooting problems.

Doorbell Systems Basics

Doorbells are typically connected by low-voltage wires that run through your home’s walls. Most wired doorbells consist of three main parts:

• The button: This is located at the entrance and is what visitors press to activate the doorbell.
• The chime: This unit is inside the house and produces the sound when a visitor presses the button.
• The transformer: The transformer is usually found in the basement or utility area. It converts household 120-volt current to low-voltage for the doorbell system.

Diagnosing the Problem With Your Doorbell

Before you can fix your doorbell, you need to identify the source of the problem. In some cases, this may be relatively easy.

• Buzzing instead of ringing: This typically indicates a problem with the chime unit.
• Continuous ringing: A stuck button or short in the wiring could be the cause of that continuous ringing.
• Weak or intermittent sound: This might suggest a partially faulty component or loose wiring.

However, if your problem is simply that you get no sound when the button is pressed, the issue could like with any of the components: the button, transformer, chime, or wiring. We’ll talk more about figuring out the cause of this is your issue.

Tools and Materials Needed

Gather your tools and other items you’ll need to figure out your doorbell issue. This includes: 

• Electrical tape
• Electrical toner
• Multi-bit screwdriver
• Replacement chime unit (if necessary)
• Replacement doorbell button (if necessary)
• Replacement transformer (if necessary)
• Voltage tester
• Wire nuts
• Wire strippers

Step-by-Step Diagnosis Process

Before beginning any electrical work, always turn off the power at the circuit breaker, even if it’s a low-voltage system. Use a voltage tester to confirm that the power is off before proceeding.

Step 1. Inspect the Doorbell Button

Remove the doorbell button from the wall, and check for any visible damage or corrosion on the button or wires. Test the button for continuity using a multimeter if you have one. Clean the contacts or replace the button if necessary.

Step 2. Test the Transformer

Locate the doorbell transformer, which you might find in the basement or utility area. Use a voltage tester to check if the transformer is producing the correct voltage (usually 16 to 24 volts). If the transformer is not functioning properly, you may need to replace it.

Step 3. Check the Wiring

Inspect the wiring at the button, transformer, and chime for any visible damage or loose connections. Use an electrical toner to trace the wires to test continuity throughout the system.

Repair or replace any damaged wiring as needed.

Step 4. Examine the Chime Unit

Remove the cover from the chime unit, check for any visible damage or loose connections. Clean the unit and tighten any loose screws or connections. If the chime unit is faulty, you may need to replace it.

Replacing Doorbell Components

When you figure out what’s not working, the easiest way to fix your doorbell system is to simply replace the malfunctioning component. We’ve broken down the steps you need to take to make those replacements below. Again, cut the power at the breaker before beginning electrical work.

Replacing the Doorbell Button

Disconnect the wires from the old button. Connect the wires to the new button, making a secure connection. Mount the new button to the wall, using anchors if necessary.

Replacing the Transformer

Disconnect the wires from the old transformer and remove it. Install the new one by connecting the wires, following the manufacturer’s instructions. Restore power and test the system.

Replacing the Chime Unit

Remove the old chime unit from the wall and disconnect the wires from the old unit.

Connect the wires to the new chime unit, mount the new unit to the wall, and test the system to make sure it works. 

Additional Troubleshooting Tips for Doorbells

If you’ve gone through replacements and repairs and your doorbell still doesn’t work, you may need to further investigate the issue or make some changes to your doorbell system. Here are some tips: 

• Check for loose wire connections: Check that all points in the system are secure.
• Consider using a wireless doorbell system if wiring issues persist: Wireless systems can bypass complex wiring problems.
• Make sure that the transformer is securely mounted and properly grounded: A loose or ungrounded transformer can cause issues.
• Verify that the voltage output from the transformer matches the requirements of your doorbell system: This step is crucial to confirming compatibility.

Maintaining Your Doorbell System

By maintaining your doorbell system, it will continue to function properly so you can avoid any unnecessary repairs or replacements. Perform an annual inspection, checking the transformer for signs of overheating or damage.

Clean the doorbell button and remove any debris, and test the system to ensure all components are working correctly. Tighten all wire connections at the button, transformer, and chime

When to Call a Professional for Doorbell Repairs

While DIY enthusiasts can handle many doorbell repairs themselves, there are times when it’s best to leave it to an electrician. Those situations include: 

• If you’re uncomfortable working with electrical systems, even low-voltage ones.
• When the problem involves the home’s main electrical system.
• If you need to run new wiring through walls or ceilings.