Central heating control broken - replace with Nest?

piccalilli82

My block had a power cut for several hours the other day and when the power came back on my central heating control seemed completely dead.

The boiler (Vaillant ecoTEC plus 831) and thermostat (Honeywell DT90E) seem fine and the hot water is working but the LCD display on the heating programmer (Danfoss TS715SI) is blank with no LED light. I've tried take it off the base to check if there was an obvious battery or fuse and re-mounting as well as resetting it but no joy. If I were to replace this unit like-for-like with another Danfoss can anyone tell me if that would be likely to solve my problem?

Alternatively if I'm likely to need a professional to investigate I am considering getting a Nest (or equivalent) replacement rather than spending anything on an older system. The Honeywell thermostat on the wall in hallway is battery powered but it's been installed over a hole in the wall where there a couple of red cables. Is this likely to be somewhere a Nest could be easily connected to the mains?

Any advice appreciated, thanks

Doozergirl

The Nest is wireless.

ossie

Doozergirl wrote: »

The Nest is wireless.

Just like your Wi-Fi wireless router, Nest Thermostat needs to be wired for power, but it connects to the Internet wirelessly.

piccalilli82

Yes I understand that Nest communicates to the heat link wirelessly but it needs power by usb or the mains. I read some other forums on this but got a bit lost on what V supply it needs and whether the old cables behind my current thermostat could be easily connected to it/supply the correct power.

Alex1983

That's what lets the nest down, you'd be better off with a hive, the hive stat takes batteries.

I_have_spoken

Unless you want/need the remote control of the Nest with mobi app, I'd got for a Digistat+3 RF - https://www.heatingcontrolsonline.co.uk/acl-drayton-invensys-digistat-plus-three-wireless-programmable-thermostat-p-97.html

The 7 day wireless programmable room thermostat will replace your thermostat and controller, plus wall unit is battery operated.

piccalilli82

Hmmm, I don't see the Nest saving me much money particularly but I do quite like the remote control and/or geofencing aspect as my schedule is quite erratic.

I'm basically hoping there is a dead simple (and cheap!) solution to get my current set-up working again that I can do myself. If I need to get a tradesperson in I think I will go for a 'smart option'

Does anyone have particular experience with Nest or Hive? A few reviews i read seemed to suggest Nest had the edge (plus Hive has that awful advert song!) but I'm open to suggestions.

What would you expect to pay for installation of a smart thermostat? (in London). I figure I should get a boiler service at the same time. Would a general heating engineer be able to cover this or do you need to get specialist 'smart' installers in?

ladymarmalade222

I love my Nest and would not be without it.

I do not have a regular routine lifestyle so love that it switches off when I move away from home. I have also reduced my bills a lot as I can switch it on via my phone for 15 mins to warm up the lounge where as when I used to switch my heating on manually I found I left it on longer due to forgetting.

If you do get a Nest it will take a couple of weeks to learn your lifestyle and you may also have to change a couple of settings. There is a warm up setting where it learns how long it takes to warm up to temperature eg in the morning but I found it was switching on a little too early. Also they have just added a function to avoid legionnaires disease so if your water is not heated for 2 hrs in a certain period it heats up to prevent it. I switched it off as it was coming on too much.

The control on your phone is great though. If you are away you can put on your heating whilst on your way home or have hot water for a bath.

I would not be without mine now and will always replace with a Nest.

I_have_spoken

Nest have a list of installers - https://nest.com/uk/nest-pro-installation/?from-footer=true

Gloomendoom

We have a Hive. I fitted it myself. I think it took around 20 minutes. The most involved part was drilling the holes in the wall to mount the thermostat.

Like the Nest, it is boon if you have an irregular lifestyle.

TheCyclingProgrammer

piccalilli82 wrote: »

Yes I understand that Nest communicates to the heat link wirelessly but it needs power by usb or the mains. I read some other forums on this but got a bit lost on what V supply it needs and whether the old cables behind my current thermostat could be easily connected to it/supply the correct power.

The Nest thermostat can also be powered by a 12v supply from the heat link, which is how I've wired mine. No plug on show.