C-Wire for Nest Thermostat with WeilMclain Ultra 155 Boiler and 13 Honeywell Zone valve

Lordofthering

Hi,
WeilMclain Ultra 155 Boiler and 13 Honeywell Zone valve installed in my house. I have most of the nest thermostat (Learning and Nest E) and all of them are working fine without having extra C wire. Recently I replaced old non smart thermostat for my one of the zone with new NEST thermostat (https://store.google.com/product/nest_thermostat?hl=en-US) and it is asking me to add C-Wire. Weird but true.

For time being I decided to add C-Wire using external 24V adapter by running two wire from same room but it started complaining that it can damage my system so I removed them.

Now I am thinking of buying one of the google power connector (https://store.google.com/product/nest_power_connector?hl=en-US) and installing at Boiler level.

Question is where do I wire this connector to ?

-- I have 4 separate 120 to 24 V transformer with C and R output which are wired to provide power to Zone valves.
-- My all thermostat has only two wires and I cannot send C wire power separately so it has to go using one of the two (Red and White) wire. If wire would have more than 2 wires, I can separately send C via third wire but it is not possible and I want to avoid re-running new wire.

Do I wire my 24 power connector at Zone valve ? If yes how wiring will look like ?

note: I am very familiar with my system since i have installed this boiler by myself two years ago. I am not sure if I can add wire from my Ultra 155 which can provide this power.

Any hint will help.

Jamie Hall

If you can't run a third wire, you will have to use a wall wart solution directly to the thermostat. Either that or junk the Nest. I've heard they make good hockey pucks.

Lordofthering

Do you know how exactly i should wire directly from Wall 24 Connector ? my adapter does not tell me R or C wire. I did wire but I was not sure if that was wired correctly and google complained.

EBEBRATT-Ed

Regardless of what Nest tells you with all their gimmicks without a c wire to the stat they will fail in time and become unreliable. I can't imagine spend the money for 13 of those

Zman

People in the HVAC industry see controls as simple terms like power supplies, switches, relays, and loads.

Nest looks at it entirely differently. They see it as how can they sell as many devices as possible and gather as much data as possible. The fact that they only work 95% of the time is not important to them.

If you can produce a document showing how the circuitry in that gizmo works, someone here can explain to you how to install it. The nest products I have seen use capacitors and other power stealing tricks to allow them to run without conventional wiring, sometimes. Until Nest publishes how they accomplish this, real tech folks will not be interested in understanding (or working on) them.

The only thing I can think of that is worse than a 13 (micro) zoned system, is a system with 13 Nests. Why would you want that many different temperatures in your house?

Lordofthering

Zman, Regrarding to your question: "The only thing I can think of that is worse than a 13 (micro) zoned system, is a system with 13 Nests. Why would you want that many different temperatures in your house?"

I have baseboard heat with 13 zone preinstalled. It allows me to control each room separately. It saves me 100s of dollar every month. House is 30 year old.

Zman

$100s a month surprises me. What type of fuel? What climate?
I think if this were mine I would be combining zones to cut down on inefficient boiler short cycles.

pecmsg

Lordofthering said:

Zman, Regrarding to your question: "The only thing I can think of that is worse than a 13 (micro) zoned system, is a system with 13 Nests. Why would you want that many different temperatures in your house?"

I have baseboard heat with 13 zone preinstalled. It allows me to control each room separately. It saves me 100s of dollar every month. House is 30 year old.

I doubt that.

Lordofthering

pecmsg said:

Lordofthering said:

Zman, Regrarding to your question: "The only thing I can think of that is worse than a 13 (micro) zoned system, is a system with 13 Nests. Why would you want that many different temperatures in your house?"

I have baseboard heat with 13 zone preinstalled. It allows me to control each room separately. It saves me 100s of dollar every month. House is 30 year old.

I doubt that.

Why would you doubt that ?. I have tested my system with turning on all zone and keeping it on as if I have only two zones and it resulted in $1400 bill. Where as controlling all zone separately as per need, cost me $300-$600 per month depends on month. I have 6500 sqft house.

Here is the preview of installed system.

Lordofthering

Zman said:

People in the HVAC industry see controls as simple terms like power supplies, switches, relays, and loads.

Nest looks at it entirely differently. They see it as how can they sell as many devices as possible and gather as much data as possible. The fact that they only work 95% of the time is not important to them.

If you can produce a document showing how the circuitry in that gizmo works, someone here can explain to you how to install it. The nest products I have seen use capacitors and other power stealing tricks to allow them to run without conventional wiring, sometimes. Until Nest publishes how they accomplish this, real tech folks will not be interested in understanding (or working on) them.

The only thing I can think of that is worse than a 13 (micro) zoned system, is a system with 13 Nests. Why would you want that many different temperatures in your house?

Here is the schematic of wiring for one of the zone

pecmsg

Lordofthering said:

Zman, Regrarding to your question: "The only thing I can think of that is worse than a 13 (micro) zoned system, is a system with 13 Nests. Why would you want that many different temperatures in your house?" I have baseboard heat with 13 zone preinstalled. It allows me to control each room separately. It saves me 100s of dollar every month. House is 30 year old.

I doubt that.

Why would you doubt that ?. I have tested my system with turning on all zone and keeping it on as if I have only two zones and it resulted in $1400 bill. Where as controlling all zone separately as per need, cost me $300-$600 per month depends on month. I have 6500 sqft house. Here is the preview of installed system.

Hundreds?

Lordofthering

pecmsg said:

Lordofthering said:

pecmsg said:

Lordofthering said:

Zman, Regrarding to your question: "The only thing I can think of that is worse than a 13 (micro) zoned system, is a system with 13 Nests. Why would you want that many different temperatures in your house?"

I have baseboard heat with 13 zone preinstalled. It allows me to control each room separately. It saves me 100s of dollar every month. House is 30 year old.

I doubt that.

Why would you doubt that ?. I have tested my system with turning on all zone and keeping it on as if I have only two zones and it resulted in $1400 bill. Where as controlling all zone separately as per need, cost me $300-$600 per month depends on month. I have 6500 sqft house.

Here is the preview of installed system.

Hundreds?

I really hate to argue on such thing but $1400 vs max $600. you figure it out.

pecmsg

If you say so!