Smart Home Wiring in London: Smart Switches, Doorbells and Thermostats

Smart switches, video doorbells, smart thermostats and app-controlled lighting are now common in London homes. Many are sold as easy to fit yourself, but older wiring often makes the job harder than the box suggests. This guide explains the common snags and when to call an electrician.

Smart light switches and the missing neutral

Many smart switches need a neutral wire at the switch to power themselves. In most older UK homes, the switch only has a live and a switched live, with no neutral. That is why some smart switches flicker, buzz or simply do not work. Options include choosing a switch designed to work without a neutral, using smart bulbs instead, or having a neutral run to the switch, which is easiest during a rewire or redecoration.

Video doorbells

Battery doorbells need no wiring, but need regular charging. Wired doorbells usually run from a low voltage transformer, often near the consumer unit or an old bell push. If the old bell wiring is damaged or there is no transformer, a new low voltage supply is needed. Mains wiring should never be connected directly to a low voltage doorbell.

Smart thermostats and heating controls

Many smart thermostats replace an existing wired room thermostat and need a power supply at the boiler or wiring centre. Combining a smart thermostat with a heat pump or electric heating may need extra controls. Our guide to heat pumps and your electrics covers the electrical side of heat pump controls.

Hubs, Wi-Fi and data points

Smart devices rely on good Wi-Fi. A wired data point to a central spot, or a mesh system, makes everything more reliable. Our guide to home office electrics covers data cabling.

Safety and paperwork

• Switch off at the consumer unit before changing any switch or fitting.
• Check fittings suit the zone in bathrooms and are rated for outdoor use outside.
• Replacing like for like is usually not notifiable, but new circuits are.

Our guide to EICR, EIC and Minor Works certificates explains which paperwork you need.

Book an electrician

Energy North Ltd fits smart switches, doorbells and controls across North, East and West London with City & Guilds certified electricians, and can usually attend within 48 hours. See our EICR service.