Doorbell Wiring 2025: Do Smart Doorbells Need Wiring?

If you’re thinking about adding a video doorbell, the first question is usually, “Do I have to run wires?” The short answer for most UK homes is: it depends. Some models love a steady power feed, while others run just fine on a battery. Below we break down the key choices, cost factors, and a step‑by‑step install plan so you can decide what works for you.

Wired Doorbells – What You Need to Know

A wired doorbell connects to the existing doorbell transformer that powers your old chime. In the UK the standard voltage is 16–24 V AC, and most modern smart doorbells are built to accept that range. If you already have a transformer, you’ll need a two‑core cable (usually 2.5 mm²) that runs from the transformer to the doorbell housing. The big plus? Continuous power means you never worry about battery life, and video quality stays consistent day and night.

Installing a wired unit isn’t hard, but you should follow these steps:

1. Turn off the mains at the fuse box.
2. Locate the transformer – usually near the consumer unit or under a stairwell.
3. Measure the voltage with a multimeter to confirm it’s within the 16‑24 V range.
4. Run the cable through the wall cavity, using a fish tape if needed.
5. Connect the cable to the doorbell’s terminals (often marked + and –).
6. Re‑attach the chime wires to the transformer, then restore power.

Test the doorbell by pressing the button; the chime should ring and the video feed should appear on your phone.

Battery‑Powered Doorbells – When They Make Sense

Battery‑powered models are perfect for renters or anyone who can’t easily run wires. They typically use a rechargeable lithium‑ion pack that lasts anywhere from 6 months to a year, depending on motion‑trigger settings and video resolution. The trade‑off is you’ll need to recharge (or replace) the battery occasionally, and you may see lower video quality at night unless the unit has built‑in LED lighting.

Installation steps are even simpler:

1. Charge the battery fully using the supplied USB cable.
2. Mount the bracket on the wall with a drill and appropriate anchors.
3. Snap the doorbell onto the bracket, attach the optional power‑over‑Ethernet (PoE) adapter if your model supports it.
4. Connect the device to your Wi‑Fi network (2.4 GHz is recommended for stability).
5. Download the companion app, follow the on‑screen pairing instructions, and you’re live.

Battery models often include a low‑battery alert in the app, so you won’t be caught off guard.

Which option saves you more money? A wired doorbell usually costs a bit more upfront – you might need a professional electrician if you’re not comfortable with wiring, and the transformer can add £30‑£50. Battery units are cheaper to install but may require a new battery every year, adding £10‑£20 to your ongoing costs.

In the UK, you also need to think about chime compatibility. Most wired smart doorbells work with traditional mechanical chimes, but some newer models need a digital chime or an added speaker kit. Check the product specs – manufacturers often list a “UK chime compatibility” badge.

Finally, remember Wi‑Fi. Even a wired doorbell still needs a stable internet connection for video streaming and notifications. If your router sits on a different floor, consider a Wi‑Fi extender or a mesh system to keep the signal strong at the front door.

Bottom line: If you have a transformer and don’t mind a short DIY job, go wired for reliable power and crisp video. If you’re renting, want a quick install, or can’t run cables, a battery‑powered doorbell is a solid choice – just keep an eye on the battery life. Either way, you’ll get a modern doorbell that tells you who’s at the door, whether you’re in the kitchen or on the train.