Nest install with possibly zoned system

[mike3105]

Hi everyone,

Any help is greatly appreciated.

I'm installing a nest V3 on my Alpha Intec 40GS combi boiler, and it appears to be 90% of the way there, but I think I need to get it to switch a zone control in the boiler. I have two zones, z1 which is replacing a wired controller with the nest, and z2 which is a wireless controller. The z1 controller was directly linked to the boiler, so not talking to a zone controller, z2 I think is talking to a zone controller.

The boiler manual is here (p.39 for the wiring): http://www.alpha-innovation.co.uk/custom/upload/instructions/InTec/New InTec 30-40GS ErP Inst and User 0515.pdf

Basically, 1&2 (which didn't have a link) are going to 2&3 on the nest, and requesting the heating on is making the boiler fire up, but the radiators aren't getting hot. I'm thinking that I need to connect something to a valve to make it send the heat to the z1 radiators?

I'm a little stuck here, and would resort to getting a pro in but there's a rather long wait at the moment.

Attached are the pictures I used for the install.

Thanks,
Mike

 

[jackthom]

If the heating is zoned there should be some motorised valves in the pipework which would open when that zone required heating. Normally the thermostat for a zone would directly control the corresponding motorised valve, which would open when heat was required and also tell the boiler to fire up.
Your connection of the thermostat directly to the boiler would not seem to allow for the opening of any zone valve.
Some pictures of the system would be useful.

 

[mike3105]

Sorry for the really slow reply. It's been a horrendous work week.

I've managed to work it out, and will put the solution here for any others in the future. And jackthom, thank you for popping along and trying to get involved even with a dodgy description from me.

It turns out what I have is a passive two zone system with a combi boiler. So I have two zone valves which are only fed by a switched live and a neutral. The relay from the boiler was supplying the switched live, and I managed to trace which zone was which with a meter, prodding away at the wires.

So the nest is now up and running. The wire which was in 55 on the relay board was giving a switched live to Z1 valve. Z1 is where I wanted to put the Nest. So, the Heat Link is hooked up with L,N&Gnd going to those on the 230V supply. Terminal 1 on the boiler goes to the switched live on the Z1 valve and 2 on the heat link. Terminal 2 goes to 3 on the heat link. All sorted! Tested with the meter (and my hand against radiators with the nest and Z2 thermostat on) and the valves are working as expected.

If you have any questions please ask. Hopefully this might help someone with anything similar to this slightly unique set up I have here.