Aqara · Doorbells and cameras

Aqara Doorbell Camera G400 Installation in London

Updated 1 November 2026

The G400 Wired (model DB-C03E, or DB-C03D for the Select version) has no battery: it runs from your bell transformer or from a PoE network cable. Aqara's transformer table marks 8 V and 10 V units as not recommended, and many UK bell transformers give only 8 V; Aqara also says the G400 does not work with a traditional chime. A vetted JACK pro in London picks the supply with you, fits the doorbell and its plug-in chime and sets it up, for a fixed price in the JACK app before you book.

In short

Yes, a vetted JACK pro in London wires the Aqara Doorbell Camera G400 to a bell transformer Aqara recommends, from 12 V at 12 VA or more up to 24 V, or powers it over one network cable from an 802.3af PoE switch. The G400 has no battery, and Aqara does not recommend 8 V or 10 V transformers for it. Aqara says it does not work with your existing traditional chime, so it uses Aqara's plug-in chime instead.

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Doorbell Camera G400: key facts

Model: DB-C03E; the Select version is DB-C03D Source: Aqara: Doorbell Camera G400 (Wired)
Transformer power: 8–24 V AC at 1.3 A, or 8–24 V DC at 0.8 A Source: Aqara: Doorbell Camera G400 (Wired)
PoE: IEEE 802.3af (48 V) Source: Aqara: Doorbell Camera G400 (Wired)
Transformers Aqara recommends: 24 V at 12 VA or more, 18 V at 18 VA, 16 V at 16 VA or 12 V at 12 VA; 8 V and 10 V are not recommended Source: Aqara: Doorbell Camera G400 (Wired)
Existing chime: Does not work with your existing traditional chime; Aqara's plug-in chime is used instead Source: Aqara: Doorbell Camera G400 (Wired)
Network: Ethernet or Wi-Fi 6; RTSP and ONVIF Source: Aqara: Doorbell Camera G400 (Wired)
Recording: microSD card up to 512 GB; Apple's HomeKit Secure Video requires iCloud+ and an Apple home hub Source: Aqara: Doorbell Camera G400 (Wired)
Weather: IP65 Source: Aqara: Doorbell Camera G400 (Wired)
Security updates: To 31 December 2029 in Aqara's UK statement for the G400 Wired (checked 1 November 2026) Source: Aqara UK PSTI statement: Doorbell Camera G400 Wired (PDF)

Device facts come from Aqara's product pages, its UK and EU store, the Aqara UK Shop and Aqara's own Amazon UK listings, linked beside each fact. Aqara often sells one product under two codes and uses EU models in the UK, so check the name and code on your box or order and send it with your request. Last checked 1 November 2026.

How the Doorbell Camera G400 is powered and mounted

With no battery inside, the G400 is only as good as its supply. Aqara's spec allows 8–24 V AC at 1.3 A, but its own transformer table recommends 12 V at 12 VA or more, 16 V at 16 VA, 18 V at 18 VA, or 24 V at 12 VA, and marks 8 V and 10 V as not recommended. Many UK bell transformers give 8 V at about 8 VA, so reading the one on your wall comes before anything else.

The other route is Power over Ethernet. One network cable from a PoE switch or injector to IEEE 802.3af carries power and data together, which also puts the doorbell on a wired connection for RTSP and ONVIF, the streams home recorders read. PoE is extra-low voltage on data cable with no new circuit, so it is not notifiable work; the effort goes into the cable route from inside to the door.

Aqara is plain that the G400 does not work with a traditional chime, so the pro takes the old chime out of the doorbell circuit and the Aqara chime plugs into a socket indoors. Recordings go to a microSD card of up to 512 GB, or to your own recorder over RTSP, and Apple Home users need iCloud+ and an Apple home hub for HomeKit Secure Video.

What the pro checks first

The transformer's voltage and VA, set against Aqara's table, where 8 V and 10 V units fall out
Where the transformer sits: a plug-in, a fused spur, inside a mains chime box, or in the consumer unit
For PoE, where a switch or injector can live and how a network cable reaches the door
A uPVC or composite frame, which may have steel reinforcement inside, so the cable often goes through the wall beside it instead
The old chime, which comes out of the doorbell circuit

What the pro does on the Doorbell Camera G400

Supply settled first: your transformer if Aqara's table allows it, a replacement, or a PoE cable
Old chime taken out of the circuit so the bell wires feed only the G400
Aqara's plug-in chime placed in a socket where you will hear it
For PoE, the network cable run, terminated and sealed where it passes through the wall
microSD card fitted, and RTSP or ONVIF switched on if you record to a home system
Motion zones and privacy settings set, then a test press

How the Doorbell Camera G400 installation goes

1Supply agreed from your photos: existing transformer, a replacement or PoE
2Bell circuit isolated before any wire is touched
3Transformer replaced on the same supply if needed, or the PoE cable run
4Bracket fixed and the doorbell connected
5Old chime taken out of the circuit and the Aqara chime plugged in
6G400 added in Aqara Home over Ethernet or Wi-Fi 6, recording set, and a test press checked

Before you book: what to send

A readable photo of the transformer label
A photo of the door, the frame and the bell push you have now
For PoE, where your router or network switch is and roughly how far it is from the door
Whether you record to a home system, such as an NVR or Home Assistant, or only to the app
In a flat or a rented home, consent for any cable through the wall or frame

Who replaces the transformer for a G400?

Aqara says to replace or upgrade the transformer with professional help if needed. Who does it depends on where the transformer is:

A plug-in transformer: no mains work, just a cable route
A transformer on a fused spur or the same circuit, replaced like for like: mains work that is not notifiable in England, so ask your pro for a Minor Electrical Installation Works Certificate
A transformer inside a mains chime box: opening it is mains work, handled in the same way
A new transformer on a spare way in the consumer unit: a new circuit, notifiable, for a registered electrician, which JACK does not book

A new transformer is added at cost and agreed with you before booking.

Is PoE the better way to power a G400?

Often, where a cable can reach the door:

One cable carries power and data, so a weak Wi-Fi signal at the porch stops mattering
It needs a PoE switch or injector to 802.3af; JACK sells neither, so you buy it or it is added at cost, agreed before booking
Through a solid London wall the cable goes in a sleeved, sealed hole; with a uPVC or composite frame it usually goes through the wall beside it
On a flat's front door onto a shared corridor, no cable goes through the fire door or its frame

Which UK transformers suit the G410 and G400?

Will your bell transformer run the G400?

Aqara's transformer table for the G400 Wired, and what the pro does with each.

Transformer on the wall	Aqara's view	What the pro does
8 V, the rating of many UK bell transformers	Not recommended	Replaces it, or uses PoE
10 V at 10 VA or more	Not recommended	Replaces it, or uses PoE
12 V at 12 VA or more	Recommended	Wires it as it is
16 V at 16 VA or more	Recommended	Wires it as it is
18 V at 18 VA or more	Recommended	Wires it as it is
24 V at 12 VA or more	Recommended	Wires it as it is

Some multi-tap bell transformers share about 8 VA across their 8, 12 and 24 V outputs, which is below every row Aqara recommends.

How is Aqara installation priced in London?

A vetted pro prices your Aqara job from the models and your photos, and the JACK app shows that fixed price before you book.

Full pricing guide for Aqara installation

Frequently asked questions

Does the Aqara G400 work with my existing doorbell chime?

No. Aqara says it does not work with your existing traditional chime, and it uses Aqara's own plug-in chime instead. The pro takes the old chime out of the bell circuit and plugs the Aqara one into a socket indoors.

Can the Aqara G400 run on PoE?

Yes, from an IEEE 802.3af (48 V) PoE switch or injector over a single network cable, which also gives it a wired network connection for RTSP and ONVIF. The switch or injector is yours to buy, since JACK does not sell devices.

Does the Aqara G400 have a battery?

No, it is wired only. If your bell transformer is 8 V and no network cable can reach the door, the Aqara G410, which runs on six AA batteries or a 12–24 V supply, may suit the door better.

How long will Aqara support the G400 with security updates?

Aqara's UK product-security statement gives the G400 Wired a defined support period to 31 December 2029, the latest date among Aqara's current doorbells (checked 1 November 2026).

How much does Aqara Doorbell Camera G400 installation cost in London?

It is a fixed price for your Doorbell Camera G400, worked out by a vetted pro from the model, a photo of where it is going and what power is there now, and shown in the JACK app before you book. Other devices can go on the same booking for one price. If you would rather pay for time, hourly hire for smart home is typically £45–£95 per hour as a guide.

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Sources

The device facts and rules on this page come from these pages, checked on 1 November 2026.

Jack All Trades (JACK) is an independent London service. It is not part of, affiliated with or endorsed by Aqara or Lumi United Technology Co., Ltd., which makes Aqara products. Aqara product names are used only to describe the devices JACK pros fit and set up; prices are set by JACK pros, not by Aqara, and JACK does not sell Aqara devices.

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