How to install Power Connector with Heat Zone Valves

[cwalenta]

I have a heat only system based on oil burner with 4 zone Valves

my system is 24V and each thermostat only has an W and Rh wire (no C-wire and no extra wires)

I got with some help from community (thanks Ken !)  the regular NEST thermostat (with AA batteries) going, but it complains about insufficient power (N260 warning)

Now I want to install the Power Connector but have questions

1) I will need 4 Power Connectors, one for each zone, will my 24V transformer support 4 connectors at the same time?

2) Since my system only has R and W wires, how do I connect the C wire that will come out of the Power Connector?

pics here

thanks for any help

Christian

[Houptee]

You are better off pulling new 5 conductor thermostat cable to each Nest if possible then connect a real C wire to the common of the transformer.

Sometimes the zone valves might chatter if too much power is being drawn by the thermostats.

That can be fixed with a larger VA rated transformer.  Look at the one you have now see if there is a decal on it. Some are 24v 30VA  so you could get a 24v 40VA it supplies more current aka volt-apms but still 24volts AC.

[cwalenta]

Thanks Houptee, unfortunately there is no way I can string new cables through the walls...

it seems like that the NEST experiment is not working out in my setup, and by reading through the blogs it seems many things can go wrong (even after the thermostats have been working good for a while) - the whole thing does not sound very reliable .. I guess I will return to them to the store....

thanks

Christian

[dhx227]

I would agree with Houptee in that the BEST solution would be to pull new wire.   Barring that, then making sure you have a big enough transformer and using Power Connectors with each of your Nests is the only other option.   At least your transformer is very accessible and would be pretty easy to upgrade (it's right there in the lower left of the 2nd picture you attached).  You also need to be careful on how you wire them all together.   Given the rats nest of wires you already have, it might be worthwhile to hire somebody that knows what their doing and/or tidy everything up so it's clear what you got going where (I really hate rats nests like that).

[cwalenta]

Thanks, appreciate the feedback, will have to think about what to do next !!!

cheers,

Christian

[Jhonleanmel]

Hey folks, 

We appreciate your help here, dhx227 and Houptee.
cwalenta, I wanted to follow up and see if you are still in need of any help. Please let me know if you are still having any concerns or questions from here, as I would be happy to take a closer look and assist you further. Also I suggest reaching out to a Nest Pro technician to discuss your options for your system to be rewired for the Nest Thermostat.

Thanks,
Mel

[cwalenta]

Mel, I am fine and all set

thanks again Houptee and DHX 227 !!!

[Jhonleanmel]

Hey there cwalenta, 

Awesome — glad to hear that your issue is fixed. It looks like we can consider this one complete, so I will lock the thread shortly unless I can help out with anything else. 

Best, 
Mel