How easy to DIY replace a Nest Heat Link?

pinkteapot

OLD POST FROM MARCH 2022 - JUST  ADDED A JULY UPDATE (26/7)

Nest Heat Link (the white box that the thermostat talks to) is dead. No light on it, despite resets and power cycling. Looking online, this is a common problem. 99% sure the issue is the Heat Link, not the power supply. Nothing's tripped, house is a 2019 build, and there's one power switch for the two Heat Links (two-zone heating) and the other one is fine. 

Do you think it's feasible for a DIYer to like-for-like replace? It's "just" a plastic box with a wire going into it. I haven't taken the top off yet to look at how complex the wiring is... 

If it's not DIYable, is it an electrician or a heating engineer I need?

On a separate grumble, am also wondering how easy it is (for a professional, not me) to replace the two Nests in our house with bog standard traditional programmers and thermostats. We hate unnecessary smart stuff. The Nests aren't on the wifi and all 'learning' functions are switched off. We literally use them as traditional programmers and it's going to cost £190 to replace the dead one, which has only lasted 2.5 years!! Plus labour if I need someone to replace it for us. House was a new-build - we didn't choose Nest, and wouldn't have. I know it'd cost a chunk to replace the lot with programmers and thermostats, but we'd be a lot better off in the long run if the Nests need replacing so much more often...

FaceHead

Are the nests plugged into a plug/USB or are they wall mounted, which means there is a wire back to the boiler to give them power?

If they are wall mounted, it's entirely possible to put an old fashioned thermostat on the wall. If they are plugged in, you could replace that with a simpler wireless thermostat. 

Replacing the heatlink is a straightforward diy job. It's a like for like swap,.just putting all the wires back in the right place - just a screwdriver to attach it to the wall (using the same fixings and holes) and a small ish flathead screwdriver to secure the wires in. Take a photo of the wiring of the old one, and label any wires which have the same colours so you know what's what once you have taken it out!

Suggest getting a spare heatlink on ebay, rather than buying the whole package. Also contact goodle - they replaced my thermostat for free (only c.1 year old though)

Bendy_House

As far as I know, it should be very straight forward, perhaps even an 'unclip and replace' jobbie. I understand these are usually fitted to the location of old wall 'stats, so may even share the most common mounting plate. I'll try and conform.
Do you have a mains tester, either a meter or a volt-stick type? The first thing to do would be to TURN OFF THE POWER and remove the receiver. Then - provided you understand what you are doing - you test the correct terminal for 'live' power. If this is ok, then chances are the receiver is dead.
Personally, I would persevere with the Nest as, even as a stand-alone system, it should be as good as any alternative, and better than the vast majority. I think you may miss its simplicity (although I don't have any personal experience if them).
In short, yes, it should be easily DIYable, but I'll try and confirm when I can surf for the info.

Bendy_House

If you really wanted to replace the Nest with conventional, wall-mounted Prog Stats, again these should simply clip on the where the Nest receivers are. Provided the Nest does use the standard backplate.
You'd be able to flog your functioning Nests very easily, but I'd still suggest you give this move some more thought.

coffeehound

2.5 years' service for a moneysaving two hundred quid thermostat?

There is a video on YT of a guy (Big Clive) showing how to fix these if you have a soldering iron

pinkteapot

coffeehound said:

2.5 years' service for a moneysaving two hundred quid thermostat?

There is a video on YT of a guy (Big Clive) showing how to fix these if you have a soldering iron

Exactly!!! We’ve always had conventional programmers that cost about £60 (and you can get cheaper of course - I like Honeywell ones due to ease of use). As I said, house came with Nests - we wouldn’t have chosen them! 

Turns out warranty is 2 years so no replacement from Google as it’s been 2.5. Normally programmers easily last 10-15 years. Pigging ridiculous.

Thanks, all. Will look at the repair video, and consider eBay for a replacement if we decide to just replace like for like.

Changing to standard programmers would probably need a professional. One Nest is wired into a wall so should be replaceable with a standard thermostat, but the other is freestanding and just plugged into a wall socket for power. 

coffeehound

totally agree pinkteapot, it's a silly situation.  It's just one component that usually fails (a capacitor), but it does look fiddly to replace it to be honest.  It might be worth a google to see if any independent companies offer a repair or exchange service since it is a common failure as you noted

Bendy_House

pinkteapot said:

Changing to standard programmers would probably need a professional. One Nest is wired into a wall so should be replaceable with a standard thermostat, but the other is freestanding and just plugged into a wall socket for power. 

The freestanding Nest will likely be connecting via WiFi with a wall-mounted receiver, or a receiver positioned near the boiler. If the latter, then you'd either need another WiFi type, or have to run wires to a suitable new wall location.

If these are as porne to failure as you say - I didn't know about this - then I reckon you have a good case under the CRA. Mind you, you'd likely have to tackle the installer rather than Nest themselves (which always struck me as unfair).

ashe

Surely no one pays £200 for a nest? Quite cheap used and £100-130 new on eBay regularly. 

Bendy_House

The Nest Heat Link is seemingly battery-powered. It can't possibly be that, PinkTea?

pinkteapot

I hadn’t read anything about the Heat Link having a battery. I’d assumed it was mains as there’s a wire into it. I’ll check… 

Re action against the installer (for CRA)… I don’t have contact details as it was already in place and I don’t know who the heating subby was on the new-build. 

Re the freestanding Nest… It’s not on wifi (we’ve never connected it to our network) but yes, it’s a wireless connection between that and its Heat Link (the receiver that actually switches the boiler). Apparently they come paired as when you buy a Nest you get the thermostat and the Heat Link in the box, or there’s a way to pair them by pressing buttons.