Vaillant Ecotec 630 wiring to Nest 3rd Gen

[Deleted member 99491]

Hi,
I hope someone can answer the question or point me to an appropriate thread please.

Currently the system is wired as per the S Plan from Nest and is fully operational for both Hot Water and the Central Heating, however the issue is that the boiler switches off when HW and CH demands have been satisfied and there is no pump overrun.

Having research a number of forums and threads, the problem appears to be with the boiler connection 3 and 4 being on a loop and not wired to the Heat Link.

I would appreciate if anyone can help with the correct wiring for connection 3 and 4 into the Heat Link please.
Thanks

 

[ShaunCorbs]

Pump isn't wired to the boiler also to do the boiler wiring you need to remove the cover which requires you to be gas safe

 

[Deleted member 99491]

Thanks, of course.

There is no separate pump, it’s integrated into the boiler.

Nest Installation was carriedout by a gas safe engineer, but the install was his first Nest and followed the instructions.

Anyone can provide a wiring spec for this would be appreciated.

 

[Murdoch]

Thanks, of course.

There is no separate pump, it’s integrated into the boiler.

Nest Installation was carriedout by a gas safe engineer, but the install was his first Nest and followed the instructions.

Anyone can provide a wiring spec for this would be appreciated.

Get him back ....... to fix it

 

[Sharp Point]

I’m lost, I don’t understand the problem.


Sorry

 

[Scott_D]

Doesn't the boiler control the pump?
Is there a bypass fitted?

 

[Deleted member 99491]

Yes the boiler controls the pump, which responses to the Nest Heat Link demands, but switches off as soon as the demand is met.

There is no bypass fitted between the boiler and the Heat Link.

 

[Scott_D]

I ment a bypass in the pipework

 

[Vee]

Why would the boiler need to keep firing if the demand is met. That is as it should be. If there is no overrun surely that’s a boiler integral issue if the pump is integral nothing to do with the Nest. What boiler is it? What does the literature for the boiler say?

 

[Gasmk1]

I would imagine he hasn't fitted a permanent live to the boiler he has just switch live so the boiler cannot control its own pump overrun, need to get him back to go though his wiring again. Or someone else who knows what he is doing. Go on the nest site and look for nest approved installers.

 

[Deleted member 99491]

I ment a bypass in the pipework

Yes there is bypass in the pipe work.