How to tell if your current doorbell system will work with Nest Hello

Nest Hello is designed to replace your home’s existing wired doorbell. But some doorbell systems can’t deliver enough voltage to Nest Hello. So you must first check that it’s compatible.

Follow the steps below to see if you can replace your doorbell with Nest Hello. Or you can also find dimensions and other technical info about Nest Hello in our Nest Hello technical specifications.

1. If you don’t already have a doorbell

If you don’t already have a doorbell, you’ll probably need to have a doorbell transformer and low voltage wires installed. Contact an electrician or a local Nest Pro in your area to get a cost estimate.

2. If you have an intercom, front gate control or other integrated device

Some advanced doorbell systems have a built-in intercom, gate control or a doorbell that’s located far from your home (such as an outside gate). If you have one of these, your doorbell probably isn’t Nest Hello compatible, but you can contact an electrician or a local Nest Pro for a consultation to make certain.

3. Check how your doorbell and chime are powered

Remove your doorbell chime’s cover. Some covers simply pull
off, but others may need to be unscrewed.

Tip: Doorbell chimes, which make the sound when someone
presses the doorbell button, are usually mounted on the wall
near the front door. Many are simply box shaped, but some
chimes have decorative covers or metal tubes hanging from them.

Chime cover being removed

If you see two or more wires 




Your doorbell will probably work with Nest Hello, but you need
to check the voltage. Go to step 4.

Mechanical chime

two wires chime box

If you see both wires and batteries 




Your doorbell will probably work with Nest Hello, but you need
to check the voltage. Go to step 4.

Electronic chime

battery in electric chimebox

If you see only batteries and no wires 

Doorbell chimes that use only batteries won’t work with Nest

But in some cases, a battery powered chime and doorbell are
installed over old doorbell wires. If there are wires under your
battery powered chime and doorbell, they may work with Nest
Hello. Contact an electrician or a local Nest Pro to check that
your wiring is compatible and install a new wired chime.

Wireless chime

no wire battery chime box


If you see wire labels that aren't T, F or R 

If your chime has wires that aren’t labeled T (Trans) F (Front) or R (Rear) it might be compatible, but you should contact a local Nest Pro for installation.

4. Check the wire voltage

Nest Hello needs to be powered by wires delivering 12 - 24 V AC and at least 8 VA (in Europe)or 16 - 24 V AC, and at least 10 VA (in North America).

Note: If you have to replace your transformer at the switchboard (DIN rail transformer), contact a local Nest Pro or a qualified professional.

Tip: A traditional doorbell button consumes very little power. But Nest Hello, which replaces your doorbell button, requires more power to keep the camera active. So you’ll need to check if your existing wires can deliver enough power for Hello to work.

Use a multimeter to measure the voltage (best way)

The most accurate way to see if your doorbell is Nest Hello compatible is to measure the voltage on the wires. Multimeters that can precisely measure voltage are relatively inexpensive.

Important: Use a multimeter that has metal probes. “No contact” voltage testers (often shaped like a pen) may not be sensitive enough to give you a correct reading.

Warning: To avoid risk of shock, injury or death, always use caution when working with electricity. Remember, if you’re uncomfortable working with electrical wiring, you can have a professional electrician or a local Nest Pro do it for you.

  1. Remove your doorbell button. You may need a screwdriver.

  2. Disconnect the wires from the button - voltage can’t be accurately measured while still connected to the button.

  3. Follow your multimeter's instructions and measure the voltage on the wires behind your doorbell.

  4. If the measured voltage is between 10.8 and 30 V AC (in Europe), your wiring should work with Nest Hello.

    If the measured voltage is below 10.8 or over 30 V AC (in Europe), contact an electrician in your area to upgrade your transformer so it can work with Nest Hello.

Contact an electrician or a Nest Pro (easiest way)

A trained electrician or a local Nest Pro will be able to measure your doorbell wire voltage, and upgrade your system if it’s not compatible. They can also install Nest Hello for you.

Find your doorbell transformer's voltage 

Electrical transformers are typically labeled with a voltage rating. It’s usually molded or etched into the transformer’s body.

However, transformers can be difficult to locate. Common places for transformers are inside your doorbell chime box, near your breaker or fuse box, or in the basement or crawl space under your home.

Tip: If you can see wires leading out of your chime or doorbell, you may be able to follow them to your transformer if it’s installed nearby.

  • If your transformer is labeled anywhere from 12 to 24 Volts AC and 8 VA in Europe (or from 16 to 24 Volts AC and 10 VA in North America): Your doorbell should be compatible with Nest Hello.

  • If there’s no label, if it’s labeled below 12 Volts (in Europe) or 16 Volts (in North America), or if it's labeled over 24 Volts: Contact an electrician or a local Nest Pro to upgrade your transformer so it can work with Nest Hello.

Install the chime connector when required 

The chime connector is included in the box with Nest Hello. It
helps make household doorbell systems compatible with

You must install it when you’re connecting Hello to a
compatible wired doorbell. The Nest app will walk you through
installation as part of Nest Hello setup.

common final wiring chime image

Note: The chime connector allows your existing wires to deliver constant power to Hello while protecting your chime, which might otherwise be damaged from the constantly flowing current. In addition, without the chime connector, you might experience chime buzzing or unexpected chimes. So be sure to follow the steps in the Nest app to install the chime connector.

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