Adding a thermostat to a Classic Bay 1200i.. "C" wire question.

[AH64ID]

Hi all, first post here, but have been doing some reading.

I am wanting to add a WiFi programable thermostat to my pellet stove, which is a Quadra Fire Classic Bay 1200i.

The thermostat requires a C wire, but the stove only has R and W wires.

I will be placing the new thermostat on the wall next to my propane furnace thermostat, can I simply power the pellet stove thermostat with the C wire from the propane furnace thermostat? And then connect the R and W from the pellet stove? Or would I need to use the R from propane thermost too?

What about using the R and C wire from the propane furnace and the W wire trips a relay where the pellet stove R/W are hooked up?

Thank you

 

[Lake Girl]

Sorry no one responded ... and I'm clueless on thermostats as we don't use one Welcome to the forum, keep on searching the forum as I know I saw a thread on WiFi stats. Hopefully someone chimes in with some assistance...

 

[kofkorn]

Not sure if you can get away with that. Your system needs the "C" wire to provide +24V. Then it will return it through the "R" connection. However, you won't be able to provide +24V from one system while returning it through the second system. It may work for a little bit, but I'd be concerned that you could blow the board on your pellet stove trying it.

You really need to have the ground referenced on the same system that is providing the voltage. If not, you may provide too much or too little power and could cause issues.

Not sure if you've looked at this thread yet:

https://www.hearth.com/talk/threads/installing-24-volt-wifi-thermostat-on-millivolt-stoves.114018/

This is the place I'd go to figure out how to wire up your WiFi thermostat.

 

[AH64ID]

I forgot all about this thread and wanted to bring it back up for people searching for a similar setup.

I have had a WiFi thermostat on the stove for 3 years and 2 years with the current setup.

The first year worked well but the thermostat would short cycle the stove and due to residual heat the stove wouldn't energize the heat rod and I would get random no-light conditions. My solution was to put a delay on break relay in the system. I'm going into my 3rd winter wired that way.

Parts used

Honeywell RTH6500 WiFi Thermostat
HVAC 24 VAC transformer
Packard PR290Q 24 VAC SPST Relay
ICM Control ICM203 Break On Delay Relay


I installed the 24 VAC transformer in the wood stove enclosure so that I could use a single 18/5 thermostat wire. I ran the 18/5 from the stove, thru the crawlspace, and up the wall next to my furnace thermostat.

The attached diagram shows the basic way it is wired.