Help a pellet guy out with millivolt tstat

[smwilliamson]

Got an M55 pellet stove, has millivolt tstat connections, trying to operate it with a Honeywell wifi thermostat, need 24v with c wire to run the bells and whistles, will this relay do it?

(broken link removed to http://www.morelectricheating.com/products/THERMOSTATS%20AND%20ACCESSORIES/LOW%20VOLTAGE%20THERMOSTATS/RC840%20SERIES%20RELAY%20ONLY.aspx)

 

[jebatty]

I doubt it to the point of saying no. The relay control signal requires 24vac or 24vdc. A millivolt thermostat operates on a thermopile which puts out about 0.75vdc.

This one says it will operate on a millivolt system:
http://www.filtersfast.com/P-Hunter...gn=Hunter&utm_keyword=42999&utm_content=42999

 

[smwilliamson]

I guess my question is...does the millivolt system trip the relay I posted or is it the other way around?

 

[__dan]

The millivolt system is powered by a thermocouple pile sitting in a gas standing pilot. I doubt that's what you have. It's an obsolete system for gas appliances.

http://www.enviro.com/images/manuals-brochures/brochures/pellet/enviro_pellet_brochure.pdf

This unit says it has a trimode thermostat and a fan. If I saw the factory wiring diagram, I could say for sure, but it probably has the internal 24v control power transformer, so may be directly compatible with the three wire thermostat, R, C, W. It's a question you would have to ask the factory, for their internal wiring diagram.

And no, the relay posted would not trip from a millivolt source. It could be used as an isolating relay to the millivolt system powered by an external 24v transformer.