Installing nest thermostat, help please

[Jon Baker]

Apologies, posted this in elctrics, meant to put it in heating. So i have tried to move it or delete it without success.

I have an ideal classic boiler and a lifestyle LP241 programmer, no thermostat on the system. I can turn heating and water on and off separately or together.

I want to swap the programmer for the nest heatlink and then control it with the nest thermostat third gen (which says it can control hot water).

My existing programmer has the following wires.
Live
Neutral
Earth

HW ON
CH ON
HW OFF

The heatlink appears to ask for four wires, hence my confusion. It asks for CH Call for heat (i presume this means on), CH common, HW call for heat and HW common. On the basis that hte old programmer had only heating on, i have tried not having a heating common - but nothing works. What am i missing?

Thank you.

 

[EFLImpudence]

On the basis that hte old programmer had only heating on,

What does that mean?
You listed one of the existing programmer wires as "HW ON"

Heat Com and HW Com will be the existing Live.

 

[Jon Baker]

Aha, you may have solved the problem. I will swap them and come back in a minute.
Thank you, hopefully

 

[Jon Baker]

Alas, it still doesnt work (but thanks for your interest so far).

Here is how i thought i should transfer the wires, although it has not worked. If anybody can see what i have done wrong, i wouuld be really grateful.

My first try
Old LP241. New nest
CH on. CH call for heat
HW on. HW call for heat
HW off. HW common

After reading the above post i tried the following, but no good. I must have misunderstood your comment?
Old LP241. New nest
CH on. CH common
HW on. HW common
HW off. HW call for heat

 

[EFLImpudence]

Ah sorry, I missed the HW OFF connection.

Therefore you do not have enough terminals on the nest.

What sort of boiler and system do you have?

 

[EFLImpudence]

Yes you do - HW satisfied. No. 4.

 

[Jon Baker]

Thank you for keeping on trying to help. If i can check i am about to do the right thing then....

What was Will now be
L241. Nest
CH ON. CH COMMON
HW ON. HW ON
HW OFF. HW satisfied

Thanks

 

[Echo the husky]

Come on guys it's only a Nest stat!
N Neutral
L Permanent live
1 Not used
2 Connect a wire link to the L terminal
3 Connect your Heating on wire
4 Connect your HW off wire
5 Connect a wire link to terminal 2
6 Connect your HW on wire

 

[EFLImpudence]

That doesn't look right - I mean Jon's post.

 

[Jon Baker]

Ok, so i hadnt tried any wire links. Will try your version echo, you seem to be ok with it efl

Cross fingers, il lreport back soon, off to find some wire....

 

[EFLImpudence]

Yes, I was confused with your first post saying it only asked for four wires.

 

[Echo the husky]

I've just scrolled down and noticed they do actually provide a wiring diagram in the manual!

 

[EFLImpudence]

 

[Jon Baker]

You are true gentlemen, both of you.

I couldnt make head or tail of the diagram, as i couldnt correlate it to the on/ off wires i had.

Thankd guys, i can havea bath now

 

[Echo the husky]

Good stuff!