Are Doorbells Low Voltage? What You Should Know

Knowing your doorbell’s voltage will help you install it correctly. Sending too many volts to your doorbell will cause a power surge, which could potentially cause fires and other issues. On the bright side, it’s very easy to check your doorbell’s voltage requirements.

Doorbells are low voltage because they range between 16 volts to 24 volts. A 120-volt circuit breaker sends electricity to a transformer, which reduces the voltage. You can test your doorbell’s voltage by placing a voltmeter’s probes on the electrical terminals.

Finding out if you have a low voltage is relatively simple. However, there are many types of doorbells with varying electrical requirements, so it’s essential that you test them before switching to a new one.

How to Know if Your Doorbell Is Low Voltage

To know if your doorbell is low voltage, follow these steps:

1. Remove the screws from your doorbell, then pull the doorbell out of the wall. You’ll notice two or three wires. One of the wires is called the hot wire because it goes directly to the transformer. The second wire is the bell wire, and it goes to the chime box. The last wire is the ground wire.
2. Use a voltmeter to test the voltage at the doorbell, then do the same for the chime box. Place the hot probe on the hot line (the one going to the transformer). Then, place the neutral prob on the neutral line (the one going to the chime box). Switch the probes if you don’t get a voltage reading.
3. Test the voltage coming out of the transformer. It should be the same as the voltage between the doorbell button and the chime box. SFGate reports that a doorbell’s voltage can be as low as 8 volts. However, they’re usually between 16 volts to 20 volts.
4. Check the voltage going into the transformer if you’re curious about the electrical reduction. Your doorbell transformer usually has 120 volts going into it. That being said, it can be up to 220 volts. The voltage at your doorbell’s transformer should be the same as the circuit breaker’s voltage.
5. Write down your doorbell’s voltage, then cross-reference it with the company’s listed voltage. Your doorbell should have the same electrical stats as the electrical requirements from the doorbell manufacturer.

Doorbell voltage inconsistencies can be problematic. Though they’re rare, voltage fluctuations can cause a doorbell to ignite into flames. It can also burn the transformer, spark the chime box, and more.

If you don’t have a voltmeter, I suggest the AstroAI Multimeter. It can check volts, amps, resistance, and more. The digital screen clearly displays the incoming voltage to the nearest decimal, so you’ll never have to worry about the guesswork.

Do Smart Doorbells Use High Voltage?

Smart doorbells don’t use high voltage because they’re designed to work with low-voltage bell wires coming from a transformer. However, some smart doorbells use batteries, which are still considered low voltage. Make sure you know if your smart doorbell needs a transformer before installing it.

According to Ring, all of its smart doorbells are designed to connect to low-voltage wires. They work with doorbell transformers, but you can also choose a smart doorbell that uses AA, AAA, or D batteries. These setups prevent you from having to deal with wires, which makes them much easier for most people.

That being said, faulty or damaged doorbells can overheat if they’re wired incorrectly. When the doorbell transformer overheats, it can cause fires, make loud buzzing or humming sounds, and damage the connected wires.

How Do Smart Doorbells Get Power?

Smart doorbells get power through one of these three sources:

1. Batteries
2. Low-voltage wires
3. Rechargeable battery packs

Some smart doorbells offer multiple power sources. You can choose which one suits your needs, especially if you have too many wires in your breaker box.

Choosing single-use batteries or rechargeable battery packs also helps you a lot when you’re replacing the doorbell. You can often avoid the doorbell transformer by swapping the old doorbell with a new one. All you have to do is remove the button and secure the old wires to the new doorbell.

Do I Have to Turn Off the Power to Replace a Doorbell?

You don’t have to turn off the power to replace a doorbell or a chime box, but you need to turn off the power if you’re replacing a doorbell transformer. The doorbell and the chime box can’t shock you because they carry less than 25 volts. A doorbell transformer carries 120 volts to 220 volts.

Keep these safety tips in mind when replacing a doorbell:

• When in doubt, turn off the circuit breaker going to the doorbell. While you can almost always work on a doorbell without cutting the power between the transformer and the button or the chime box, it’s better to be safe than sorry.
• You can use a voltmeter or a multimeter to test the voltage if you’re uncertain how many volts the doorbell uses. Your meter shouldn’t show more than 24 volts for the vast majority of doorbells. Test the results at each of the terminals you intend to work on.
• You don’t need to turn off the power if you’re replacing a doorbell that sticks. The wires on the back of the doorbell button don’t have enough volts to shock you. You can remove, replace, or strip any of these wires while replacing the button, all without turning off the breaker.
• There’s no need to cut the electricity if you’re replacing a battery-powered doorbell. Simply remove the doorbell from the wall and replace the batteries. Some doorbells have screws on the battery compartment. Either way, you don’t need to touch the circuit breakers.
• A doorbell doesn’t work without power, so you need to make sure the wires are secured in their terminals. If you turn off the breaker, tighten each of the wire terminals before turning it back on; otherwise, there’s a high chance of electrical arcing between the terminals and the copper wire tips.