Aqara Doorbell Transformer and Chime: G4, G410 and G400 in UK Homes

• Video Doorbell G4: a pack of six AA batteries, or doorbell wiring at 12–24 V AC or 8–24 V DC. Aqara says 24/7 recording works only when it is wired, and its Amazon UK listing says it needs 2.4 GHz Wi-Fi and does not support 5 GHz
• Doorbell Camera Hub G410: six AA batteries, or 12–24 V AC at 0.2 A or 12–24 V DC at 0.5 A. Continuous recording and RTSP streaming need the wired connection, and Aqara's instruction is to hardwire it to your existing doorbell transformer
• Doorbell Camera G400 Wired: no battery, which Aqara calls battery-free. It takes 8–24 V AC at 1.3 A, 8–24 V DC at 0.8 A, or Power over Ethernet to IEEE 802.3af
• Aqara's transformer guidance for the G400: at least 12 VA at 12 V or 24 V, 16 VA at 16 V and 18 VA at 18 V, with 8 V and 10 V supplies marked 'Not recommended'

• An 8 V AC output is below the 12 V AC minimum of the G4 and G410, so neither can be wired to it
• The 12 V or 24 V terminals of a multi-tap module are within range for both, and the pro checks the module's VA against what the doorbell draws
• For the G400, Aqara asks for at least 12 VA even at 12 V or 24 V, more than an 8 VA module gives, so on older bell wiring it usually needs a new transformer or PoE
• Where the transformer sits inside a mains-fed chime, opening it is mains work, so that circuit is isolated first

• Batteries: the G4 and G410 run on six AA cells, which suits a rented flat or a door with no bell wire, though without 24/7 recording
• A 12 V DC plug-in supply: the Aqara UK Shop sells a 12 V 1 A adapter with a UK plug for the G4 and G410, marked as a third-party accessory not made by Aqara. It plugs into an indoor socket, so the work is the cable route to the door
• PoE for the G400: one Ethernet cable from a PoE switch carries power and data at extra-low voltage, which is not notifiable
• A new transformer, swapped like-for-like on the same supply or fed from a fused spur on a circuit you already have. Neither is notifiable in England, and for the G400 Aqara itself suggests professional help to replace or upgrade one
• A transformer on its own new consumer-unit way, which JACK treats as a new circuit: a registered electrician's job that JACK does not book

• G400: in Aqara's words, it 'does not work with your existing traditional chime'
• G4 and G410: Aqara staff on its forum say neither drives an old wired bell directly
• The workaround they describe is a Dual Relay Module T2 in dry-contact pulse mode, wired to the chime, with a warning that mains wiring is dangerous and that a qualified electrician is recommended; forum replies disagree on the transformer voltage it needs
• The simpler route is to leave the old chime disconnected and use Aqara's own indoor unit

• G4 chime-repeater: up to 95 dB, and it can run from a power bank. Aqara says it also serves as a repeater
• G410 chime: 5 V 1 A over USB-C, and it holds the microSD slot used for 24/7 recording once the doorbell is wired
• Aqara says the G410 doorbell itself doubles as a hub for Aqara Zigbee and Matter devices and can act as a Thread border router, so it is planned in with the rest of your Aqara set-up

• The bell transformer's label, sharp enough to read the volts and VA, or a note that you cannot find it
• The old chime, and the front door and frame from outside
• For a G400, where the router is and a route an Ethernet cable could take
• Your Aqara model, from the box

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

What the job touches moves the price more than the device does. Pairing a hub, fixing sensors, clipping a Curtain Driver E1 onto a rail or fitting radiator thermostat heads is set-up work. A smart lock is locksmith work on the door. An H1 or H2 switch, a Dual Relay Module T2 or a 230 V blind motor is mains work on an existing circuit, priced for isolating, connecting and testing.

The home comes next: a multipoint door that needs adjusting before a lock goes on, a bell transformer too weak for the doorbell, a PoE cable through solid brick. Where a job needs a second pair of hands, your pro can ask another pro on JACK to help through the Pro2Pro feature. Several devices, Aqara or other brands, go on one booking for one fixed price.

You buy the Aqara products; JACK does not sell them. Accessories the job needs, such as a replacement cylinder, a deeper back box, a 12 V plug-in supply or a PoE injector, are agreed and added at cost before you book, and so is parking where it has to be paid for. Prefer to pay for time? As a guide, hourly hire is typically £45–£95 per hour for smart home work, £55–£110 for electrical work and £60–£130 for locksmith work, and a full-day handyman booking is a flat £350–£400 for up to 8 hours on site.