Can a Doorbell Cause a Fire? Yes, Here’s Why

Doorbells don’t carry a lot of electricity, which is why they’re rarely associated with fire risks. However, anything with electrical wires should be taken care of with caution. Doorbells aren’t the most flammable appliance in your home, but they definitely need secure wiring.

A doorbell can cause a fire if the transformer’s electromagnetic core wears out and can’t properly reduce the incoming voltage. Doorbells use 16v to 20v, while the transformer receives 120v. When the transformer can’t reduce the voltage, the electrical surge causes a short-circuit.

Throughout this post, I’ll explain why doorbells can catch on fire, how doorbell shorts happen, and whether or not old doorbell wires can be left exposed.

Can a Doorbell Catch on Fire?

Doorbells can catch on fire, especially if they aren’t wired correctly. The transformer should have two wires coming into it, both carrying 120 volts. One wire leaves the transformer to the doorbell, while the other goes to the chime box. All four of these wires need to be secured to prevent fires.

According to the Consumer Product Safety Commission, Ring recalled 350,000 Ring video doorbells in 2020 due to fire risks. However, old-school doorbells also present various fire risks, including short-circuits and exposed copper wires.

For example, a hot doorbell transformer is often an indicator that there’s too much voltage, the core is damaged, or the wire gauge is too small. If your doorbell is extremely hot and noisy, turn off the circuit breaker. You should also avoid holding the doorbell button for longer than a few seconds.

Electric blanks can catch on fire if they’re used for too long. The same issue happens when a doorbell button gets stuck. Even if you’re not holding the button, it can stick and heat the transformer. It can also warp and weaken the solenoids in the chime box.

Review these list of potential reasons a doorbell can catch on fire:

• Too many wires connected to the same circuit breaker
• Loose wire nuts in the junction box going to the doorbell transformer
• Moisture getting on the transformer and rusting the electromagnet
• Corroded electrical terminals
• Undersized circuit breaker that doesn’t have the right amperage

Doorbell fires are quite rare. That being said, it’s important to know how you can protect your home from dealing with the previously mentioned electrical concerns.

Can a Doorbell Short Cause a Fire?

A doorbell short can cause a fire if the transformer is worn down and doesn’t reduce the incoming voltage or amperage. This causes an electrical current to surge through the chime box or the transformer, causing smoke and fires.

So, what causes doorbells to short circuit and burn?

• A buzzing or damaged transformer will eventually short-circuit or stop working. While a little bit of humming is normal, it shouldn’t keep getting louder. Increasing doorbell transformer volume is usually a sign that the electromagnet is faulty.
• A doorbell can burn if the transformer terminals are broken or loose. This causes the voltage to build up, making the transformer much hotter than it should be. Tighten each of the wires at their terminals, then check if the terminals are tightened to the transformer.
• Malfunctioning circuit breakers can short-circuit a doorbell. Unfortunately, many homeowners often think there’s something wrong with the transformer or the chime box when this happens. That being said, you should use a multimeter to ensure the listed amps and voltage are present.
• Electrical arcing happens when one or more electrical wire touches a metal surface and sparks. This is one of the many reasons tower fans catch on fire. The wires or plug prongs have to make complete contact with the terminals. If they’re loose or distanced, electricity will jump from one side to the other, causing sparks or fires.
• Using the wrong wire gauge can cause complications for your doorbell. Always check your doorbell’s required wire gauge. Most doorbells, chime boxes, and doorbell transformers require 18-gauge electrical wires.

On the bright side, all of these shorting issues are avoidable. Secure connections and annual maintenance will prevent your doorbell from short-circuiting or catching on fire.

Doorbells use fairly low amounts of power. Before you leave a doorbell’s copper wires exposed, read on for a few safety suggestions.

Can You Leave Doorbell Wires Exposed?

You can’t leave doorbell wires exposed because they carry electricity. If your doorbell isn’t connected to a transformer, you should cap the wires with wire nuts. Never use bare copper wires anywhere in your doorbell’s assembly because they can cause fires.

If your doorbell’s wires are exposed, go through this process to protect them:

1. Switch all bare wires with sleeved wires (red or black for hot, white for neutral, and green for grounding wires). Choosing the right wire colors will help you with future electrical projects. I can’t tell you how many times I’ve opened an electrical panel with every wire being black or red.
2. Place wire nuts at the tip of each exposed wire that isn’t connected to a terminal. The Spruce explains you should cap each wire with a wire nut because it stops the current. You can’t get shocked by the copper portion that’s tucked in the wire connector.
3. Low-power doorbell wires can be exposed, but you should remove them from their terminals if possible. Although doorbells don’t work without power (they need batteries or electrical wires), they carry a small amount of voltage. Most doorbell wires are called bell wires.
4. Turn off the circuit breaker connected to the doorbell transformer, then disconnect the transformer wires from the chime box. Your doorbell shouldn’t be in the chime box, but it can be mounted right by it. You can’t work on the wires between the breaker and the transformer without turning off the power.

If you don’t have 18-gauge wire nuts, try the Romeda Wire Connectors. Each kit includes 180 wire nuts, ranging from 12-gauge to 20-gauge. I’ve used this wire nut kit for multiple projects without experiencing any issues. Make sure you check each wire nut to know how many wires it can hold.

Most doorbells are low voltage, so you don’t have to worry about getting shocked.