Fitting NEST

[paulfoel]

I have a boiler, timer and room thermostat.

At the moment, timer is used to set times for both heating and hot water. Thermostat in living room is for temp (obviously).

Whats best way to install NEST in this setup. Do I replace the timer with the heatlink and the thermostat with the nest controller?

Or not?

 

[stem]

You need to give details of your boiler and the existing time and temperature controls (make & model) also, what type of system the boiler is connected to. For example do you have motorised valves? and if so is it a Y Plan (3-port motorised valve) or S Plan (2 or more 2-port motorised valves) is there a hot water cylinder? There are 100's of different combinations out there and the Nest installation will vary accordingly.

 

[flameport]

Do I replace the timer with the heatlink and the thermostat with the nest controller?

The Heatlink replaces the timer.
Old thermostat is removed completely and a wire link installed in the wiring centre.

The new Nest controller does not require any wires for control.

 

[Dan Robinson]

You need to give details of your boiler and the existing time and temperature controls (make & model) also, what type of system the boiler is connected to. For example do you have motorised valves? and if so is it a Y Plan (3-port motorised valve) or S Plan (2 or more 2-port motorised valves) is there a hot water cylinder? There are 100's of different combinations out there and the Nest installation will vary accordingly.

I don't know how you have the patience to respond to all these Nest related threads.

 

[stem]

Nor do I really, especially when quite a few don't respond. Must get a life........

 

[HERTS P&D]

Or give you a 'thanks' or 'like'!

Andy

 

[paulfoel]

Sorry for the delay.....

I've got an ideal classic FF350 boiler, drayton L112 timer, and honeywell T6360 room thermostat.

Neighbour fitted his (same setup) and fitted the heatlink directly to the boiler. And left timer there set to permanently on. Said you could not replace the timer because then you'd lose ability to control water with nest.

Dont understand that because surely timer controls water now and you're just replacing wires?

 

[stem]

The Nest provides both temperature and time control for heating and hot water. Therefore no additional time control is required. The Heatlink terminals 1 to 3 are provided to control the heating and 4 to 6 to control the hot water. If your neighbour has to retain the timer for the hot water, then either he has installed it incorrectly, or he has an early version of the Nest that was designed for combi boilers and doesn't have the hot water control facility.

You still haven't told us much about your system. I suppose we can assume from your boiler make / model that you also have a hot water cylinder, a hot water cylinder thermostat and either one or two motorised valves controlling it too.

 

[paulfoel]

The Nest provides both temperature and time control for heating and hot water. Therefore no additional time control is required. The Heatlink terminals 1 to 3 are provided to control the heating and 4 to 6 to control the hot water. If your neighbour has to retain the timer for the hot water, then either he has installed it incorrectly, or he has an early version of the Nest that was designed for combi boilers and doesn't have the hot water control facility.

You still haven't told us much about your system. I suppose we can assume from your boiler make / model that you also have a hot water cylinder, a hot water cylinder thermostat and either one or two motorised valves controlling it too.

Ah yes I think he had nest 2. But he seems convinced it needs to be conencted directly or you cant control hot water.

Yes I have hot water cylinde (in airing cupboard), cylinder thermostat - dunno what does it look like?, motorised valves - think so I'll check.

 

[stem]

Ah yes I think he had nest 2. But he seems convinced it needs to be connected directly or you cant control hot water.

That is correct. But.

Said you could not replace the timer because then you'd lose ability to control water with nest.

Is not correct.

A motorised valve looks something like this.

Untitled

• stem
• 1 Apr 2010
• 8

A cylinder thermostat looks something like this and will be mounted approx one third of the way up from the bottom of the hot water cylinder.

Untitled

• stem
• 21 Dec 2010
• 3

 

[paulfoel]

Yes it seems I have both.

To clarify, neighbour has installed heatlinke directly to boiler, and left existing timer there (but left it on constantly on to let nest control things). Hes hot same set up as me - new houses!

OK, so at the moment, wires go from boiler to timer to thermostat. Still dont understand why I can just replace whats there and utilise existing wires (dont they have ch on, hw on etc?). Also same for nest controller.

I understand it'll work if you connect directly to boiler and then just power the nest but it'll rely on wi-fi only then wont it?

What do you gain by connecting the heatlink directly? Are there more connections than already wired to timer?

 

[stem]

To clarify, neighbour has installed heatlinke directly to boiler, and left existing timer there (but left it on constantly on to let nest control things).

Are you sure that your neighbours system is exactly the same as yours? It sounds to me from your brief description as if he may have a combi boiler and no hot water cylinder. In which case, the installation is much simpler as the Heatlink just replaces a room thermostat, and any timer, which is often part of the boiler can be left permanently on.

OK, so at the moment, wires go from boiler to timer to thermostat.

I doubt that very much in your case. The timer is wired to the thermostat which is then wired to the motorised valve, not the boiler.

Still dont understand why I can just replace whats there and utilise existing wires (dont they have ch on, hw on etc?). Also same for nest controller.

Yes, that it what you should do. Remove the existing programmer and replace it with the Heatlink utilising the same wiring.

I understand it'll work if you connect directly to boiler and then just power the nest but it'll rely on wi-fi only then wont it?

I have no idea what you mean by that!

What do you gain by connecting the heatlink directly? Are there more connections than already wired to timer?

The connections are the same. The Heatlink takes over total control of the time and temperature control of the hot water and heating systems. It is much easier to remove the programmer and replace it than to try and connect them both in there are twice as many connections to make.

 

[paulfoel]

Are you sure that your neighbours system is exactly the same as yours? It sounds to me from your brief description as if he may have a combi boiler and no hot water cylinder. In which case, the installation is much simpler as the Heatlink just replaces a room thermostat, and any timer, which is often part of the boiler can be left permanently on.


I doubt that very much in your case. The room thermostat is wired to operate the motorised valve, not the boiler.


Yes, that it what you should do. Remove the existing programmer and replace it with the Heatlink utilising the same wiring.


I have no idea what you mean by that!


The connections are the same. The Heatlink takes over total control of the time and temperature control of the hot water and heating systems. It is much easier to remove the programmer and replace it than to try and connect them both in there are twice as many connections to make.

Thanks Stem. Yes neighbour has exactly the same setup - new housing estate.

Yeh I understand how the heatlink works and I thought, as you confirmed that you can just replace the existing timer with heatlink. I just dont understand why my neighbour says you need to leave the original programmer there and cable the heatlink separately He says otherwise the heatlink cant control the hot water.......

 

[stem]

No nor do I. Do you suppose that if a new house were built now with a Nest, that the installer would also have to add an additional programmer as well in order to get the hot water to work.

I suspect that your neighbour may only have connected the Nest to his central heating wiring (ie and not the hot water) and has left the original programmer there to control the hot water.

 

[paulfoel]

OK Heatlink and nest installed and working. Ended up replacing the timer with heatlink.

Nest thermo is usb connected at the moment. Original dial thermo is still there too. I guess I need to remove this.

Can I power nest thermo from this - I note is 12v only though. What about the other wires - will they provide a link to heatlink or should I leave those out and rely on wifi?