Baxi Bermuda Inset 2 and Nest Gen2 controller?

[User 1471]

Hello people,

This is my first post here. I'm just lookig for a bit of advice as to whether it's possible for me to instal a Nest Gen 2 heating controller with my existing (old) heating system.

I currently have a Baxi Bermuda Inset 2 back boiler which is controlled by a Potterton EP2002 controller, which is mounted on the wall near the back boiler in my living room. I also have a Honeywell stat in my hallway. See pic in first post in the the link bellow.

"Clever" controller for central heating? - Page 2 - Homes, Gardens and DIY - PistonHeads - https://www.pistonheads.com/gassing/topic.asp?h=0&f=207&t=946106&i=20

My system has a hot water storage tank in a bedroom up stairs above the back boiler, but I am unsure if my system is gravity fed or not.

I know for sure that in order for the CH to be on, the DHW also needs to be on.

All I really want to be able to do is turn the heating (and HW) completely on and off remotely from another location as this would allow me to switch the heating on an hour or so before I get home.

Is the Nest Heat Link even compatible with my current system?

Thanks!
Regards
Graham

 

[davesparks]

If you have to switch HW on for heating to work then it is likely to be gravity hot water,the other option being that the programmer is incorrectly set up.
In a gravity system the HW channel only signals the boiler to fire and the heat gravitates to the hot water cylinder, the central heating channel and thermostat only operates a circulating pump which pumps the heat around the radiators. The central heating control doesn't fire the boiler, this is why the hot water must be on for the heating to work.

The Nest isn't designed to work with gravity systems, though I think it could be adapted by the addition of a relay to fire the boiler when there is heating demand.

 

[User 1471]

Thank you for your response, that's very helpful I am sure I was a thread on another foeum whare somebody has done just that, with the rely. I'll see if I can find it and post back later

 

[User 1471]

I hate trying to type on a mobile phone LOL.

 

[User 1471]

Hello again, O.K. so i found the thread I was thinking about with the relay used as you described (I think), but further reading suggests that it may be possible to use the internal relays in the Heat Link to do the same thing, by adding links where rquired.

Here are the two links bellow:-

Nest Learning Thermostat 3rd Gen Hot Water Installation - https://www.briandorey.com/post/nest-learning-thermostat-3rd-gen-hot-water-installation

https://www.briandorey.com/docs/2015-12-04-nest-thermostat-install/archive-comments.pdf

That said, I'm not sure if this system is gravity fed like mine is?

I'd like to be able to repurpose the wires to the stat in the hallway to power the Nest stat, but I have yet to take a look at the wiring insided the Potterton controller and the existing Honeywell stat to see if they are connected directly, or if the wires from the stat go to the pump which I'm pretty sure is under the floorboards in the livingroom, so not so easy to get too as the access hatch is in the hallway.

Any idea?

Thanks again

Graham

 

[User 1471]

Oh, I should add, my hot water storage cylinder takes for ever and a day to heat up, so it probably is gravity fed, that would explain why it takes so long to heat up