Who Can Install a Nest Thermostat? Gas Safe Engineer, Electrician or DIY

• The HSE's code of practice, L56, gives removing or replacing electric thermostats and on/off timer switches as an instance of work outside the regulations, so Gas Safe registration is not needed for it, though competence still is
• L56 also says the regulations reach anything that could affect an appliance's gas safety, such as combustion seals and the appliance's own controls
• Gas Safe Register says a plumber or electrician could replace a non-gas part behind a boiler's decorative casing if no combustion seal, gas-carrying part or combustion control module is disturbed
• It also treats a case held on by several screws as a functional case, which someone who is not Gas Safe registered should not remove

• Under regulation 12(6A) of the Building Regulations 2010, only three kinds of home electrical work need notifying: a new circuit, a consumer unit swap, or work that adds to or alters circuits in a special location, meaning the space around a bath or shower, or a room with a swimming pool or sauna heater
• Approved Document P lists replacements anywhere, and additions or alterations outside those spaces, as not notifiable, so a Heat Link on the old programmer's circuit, or on a fused spur added outside a bathroom, needs no notice under Part P
• Work that is not notifiable should still be inspected, tested and certificated to BS 7671, so ask your pro for a Minor Electrical Installation Works Certificate
• A new circuit or consumer unit work needs a registered electrician or a building notice first; JACK books neither as part of a thermostat job, nor fixed electrical work in a bathroom

• Its UK and Ireland guide for the 3rd gen, and Google Store UK's thermostat comparison, say the Learning Thermostat should be installed by a professional; the comparison calls the Thermostat E easy to install yourself
• Google's Heat Link table lists the Heat Link E as DIY or Nest Pro, and the 3rd gen Heat Link as Nest Pro, Google's name for its installer programme
• Google's UK help page says Google does not provide, sell or take payment for installation, and that complex changes such as new wiring may need an electrician
• The installer link printed in the UK guide, nest.com/eu/install, now redirects to a bare country chooser

• Google's UK guide takes the 3rd gen Heat Link's live and neutral from the L and N circuit on the boiler or a junction box: a JACK pro connects it at a junction box or wiring centre, and a Gas Safe engineer at the boiler's terminals
• Where a home has no room thermostat, or has an integrated receiver, Google's UK installation terms place the Heat Link E beside the boiler; JACK leaves any wiring inside the boiler for that to a Gas Safe registered engineer
• OpenTherm runs on a pair of wires to the boiler's own terminals, so connecting it is boiler-side work; a pro can still swap the wall device where an OpenTherm cable already reaches the wall and the boiler end works
• Controls on an unvented (pressurised) hot water cylinder are safety devices, so they go to a G3-qualified installer

• The programmer, timer or room thermostat you have now, and the wiring centre if you can see one
• The boiler's make and model, and its underside, where the cables come out
• Whether there is a hot water cylinder, and which Nest you have

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

On heating, where the Heat Link goes moves the price most: a 3rd gen Heat Link in place of a programmer on the same wiring is the plainest job, while hot water on a cylinder, an S-plan or Y-plan wiring centre or an old wired thermostat to take out of the circuit adds to it. Anything that must be wired at the boiler itself is left out of the price and handed to a Gas Safe registered engineer.

On doorbells and cameras, power comes first: a battery doorbell or Nest Cam with a good 2.4 GHz signal is the lightest job, a weak bell transformer is swapped on its existing supply, and the Nest Cam with floodlight is priced as electrical work on your outside-light circuit. For a camera high on a gable, your pro can ask another pro on JACK to help through the Pro2Pro feature.

JACK does not sell devices, so the Nest kit is yours to buy. Accessories the job needs, such as a bell transformer, a fused spur or an outdoor junction box, are agreed and added at cost before you book, and so is parking where it has to be paid for. Several devices go on one booking for one fixed price. Prefer to pay for time? As a guide, hourly hire is typically £45–£95 per hour for smart home work and £55–£110 per hour for electrical work, and a full-day handyman booking is a flat £350–£400 for up to 8 hours on site.