Is my boiler compatible? Nest Thermostat

Sparx

Sparx

Sparx

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Joined
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Lincolnshire
Hi folks, question for any in the know or who have installed Nest Thermostats before.

Looking at purchasing and installing one in our new home we moved in earlier this year, currently we have an an old ish Glow-worm 50FF system boiler. Temp control stat in the hallway, along with this additional hot water stat in the loft with the rest of the gubbins.

I was tempted to get someone in to install it, but this seems a reasonable DIY job unless I'm mistaken? I've uploaded some photos (see spoiler tag) below, is it really as straight forward as...

1. Isolate power to thermostat/boiler (think it's on the main ring circuit anyway)
2. Swap the Drayton control stat in the loft you see for the Nest heatlink
3. Swap our downstairs temp control stat with the Nest Thermostat itself
4. Setup Nest, done?

Also unsure about the thing that looks like a breaker, I think it's a timer relay for the boiler controls? Would that still be needed with Nest or would I disconnect & remove it?

Appreciate any tips or advice :) If I'm completely wrong or if anyone knows why this will not be compatible with my boiler, let me know! Or if I should get a plumber in...

Cheers :D

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Yes there should be diy guides online. I'd hazard a guess that if it's fairly new it will be comparable but worth looking at.

I did the same with my tado and it only took a couple of hours if that.

If you were to get someone in to do it, I'd get an electrician not a plumber.
 
Yeah good shout, not sure why I said plumber - when all the works are electrical lol (tiredness kills me with newborn twins these days :o)

Just not sure about this timer relay breaker if it needs disconnecting, or kept in situ and connected up to the heatlink still... I'm sure if I watch some vids it'll inform me.
 
I had a Drayton like yours.
And a wired analogue thermostat

I had to remove the wired stat and replace the Drayton with the tado hot water/master unit.

I had to bridge the wired stat to create an always on loop.

I had to rewire the Drayton connections for the tado.
 
Be careful what you're doing with the system you have. I can tell you now that is not a standard setup up in the loft.

You have an old Y-plan in the loft, (inc old Micron boiler) connected to a modern unvented cylinder with its own stat/limit and 2-port.

But what's interesting is the fact you only have single channel timer up there (why have a controller inaccessible in the loft??) and what looks to be a time delay relay connected into the circuit. By the looks of it, connected into the UVHW circuit. Not sure why tho :confused:

What control do you have downstairs in the house?

Mick

(and yes I do this for a living)
 
@FlyingFish cheers for the input! Yeah I do find it odd the Drayton unit in the loft is up there, it appears to only control the hot water. I think this is just left to ‘On’ I was curious if that was the correct operation but our gas bills are <£20pm in the summer so far so it doesn’t seem to cause any issues.

In the hallway we have another Drayton unit which only controls the heating temperature and schedule (no hot water controls).

We had a control stat like it almost identical in our last home (was a new build) but it had both heating and hot water controls, as you’d expect…

From what the old owners told us, the previous owner before them was a plumber and installed the boiler himself. There’s a box up there too with some spares for the boiler.

Any advice be helpful ;)

Edit: I will add the boiler seems solid so far though, we’ve been here since April and the heating and hot water comes on quickly, rads warm up fast and hot water comes through quite quickly. So seems from my view to have been well looked after and maintained, or it’s just a decent old boiler maybe?

I was curious when buying if it’d need replacing soon as I saw in the paperwork how old it was, think it was c.15 years old or so? But the Nest thermostat was whether I could optimise our heating and hot water controls and schedule with winter coming…
 
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It does look like the person who installed it, knows what they were doing. It just seems a bit odd, the way it's been done.
If it was me I would rewire the wiring centre, removing the old timer, room stat/clock, relay timer etc. Depends how comfortable you are at doing that.
The existing wires going to the heating control are 240ac, and cannot be used for the Nest thermostat while still wired to the wiring center (240ac will fry the Nest stat)
That delay relay is interesting, I'd like to know how that's wired in :D Does it delay the uvhw stat? Give the heating a head start, or the dhw?

Have you done any wiring previously? Used a multimeter to test circuits etc?

Edit: I wonder if it's a delay for the uvhw 2port, for the boilers pump over run function?
Were you left any schematics?
 
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FlyingFish said:
It does look like the person who installed it, knows what they were doing. It just seems a bit odd, the way it's been done.
If it was me I would rewire the wiring centre, removing the old timer, room stat/clock, relay timer etc. Depends how comfortable you are at doing that.
The existing wires going to the heating control are 240ac, and cannot be used for the Nest thermostat while still wired to the wiring center (240ac will fry the Nest stat)
That delay relay is interesting, I'd like to know how that's wired in :D Does it delay the uvhw stat? Give the heating a head start, or the dhw?

Have you done any wiring previously? Used a multimeter to test circuits etc?

Edit: I wonder if it's a delay for the uvhw 2port, for the boilers pump over run function?
Where you left any schematics?
Click to expand...

Mine was a y plan too. But my loft looks Waaaay busier than his!
Hive doesn't handle 240v? That's shocking!
 
@FlyingFish afraid I’m not that experienced! Literally just have the confidence to dabble and become dangerous! :D Nah just not afraid to give things a go… if I knew what wires I was moving I’d prob give it a go, but from what you explained it seems maybe I should lean towards getting a sparky in… don’t believe there is any schematics either!

So should the Nest work with the 240v wiring as the loft is where the heatlink will replace the hot water stat I assume? Would my existing thermostat in the hallway not use low power wires then?
 
Sparx said:
@FlyingFish afraid I’m not that experienced! Literally just have the confidence to dabble and become dangerous! :D Nah just not afraid to give things a go… if I knew what wires I was moving I’d prob give it a go, but from what you explained it seems maybe I should lean towards getting a sparky in… don’t believe there is any schematics either!

So should the Nest work with the 240v wiring as the loft is where the heatlink will replace the hot water stat I assume? Would my existing thermostat in the hallway not use low power wires then?
Click to expand...

Mine hallway thermo was 240v
Tado could handle it.
 
The heatlink is either 240 or volt free, depends what you do with it when you wire it up for the systems requirements.
The Nest thermostat that is designed to screw in place of a wall roomstat is not 240. It is powered using the existing wires, but not connected to 240 like an old stat. So the old 240 wires from the wiring center need correctly moving over to the heatlink to power the Nest thermostat downstairs.

By the looks of things the existing system is all 240. Half the wires for the heatlink, are behind the single channel clock, the other wire required is down at the existing room stat. And those wires need re purposed to power the Nest stat. Unless you are using it on a stand.

It's all straight forward, and doable, and is just a case of rewiring the wiring center in the loft and the room thermostat. If you know about heating wiring and what's required ;)

I would probably say get someone in to do the job, if this is your first go at electrics :D
And make sure they fully understand heating wiring, controls and unvented cylinder requirements. Your most likely looking at a heating engineer (like me) that has the right qualifications, or a good sparky who knows his stuff. Do check, as heating wiring can be a funny 'grey' area between trades.

Mick
 
Hard trying to find any reliable trades these days, let alone properly educated ones in the know. It's one thing getting them to turn up, another to get the quote back, then another if they turn up and do a full days work or kick the can at 1-2pm :o

I know 2 sparks, one seems decent haven't used him yet so will ask him. I do know a good heating engineer but he's quite expensive from memory, but might see what he says. The other did our kitchen recently and whilst he seemed competent, he was sloppy and so reluctant to do much, didn't tidy any of his mess up (visited 3 times never tidied up just left a huge mess) and was a PITA to turn up on the agreed date/time he forgot so often...
 
First think that jumps out is the Merlin timer, shouldn't be like that, could be in an enclosure, looks like a modication by a factory maintenace sparks who doesn't do much outside of panels!, but likely it can be removed,depending on what its doing.

Where abouts in lincs are you? I'm LN4 (although that is a huge area!)
 
i'm going to jump on this thread as I'm considering smart thermostats too. None of them seem to have integration into hot water tanks to monitor the temperature in there, and can only control the on/off for filling it up.

I'd much rather be able to have the boiler fire up to top that up when the temp drops below Xc instead of "2 hours a day" as it currently is set up, but Nest etc don't seem to have hot water tank thermostats.

Am I missing something?
 
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