Enviro Mini & thermostat wiring

[bubble]

We are having an Enviro Mini installed in our porch within 2 weeks. My questions pertain to wiring a SMART thermostat to the stove. These are my requirements:

1) I do NOT want to rely on battery power to permanently power the thermostat.
2) I do NOT want to rely on wireless communications between stat & stove.
3) I DO want a constantly backlit display.

I'm leaning real hard towards a Lux Geo thermostat on the wall to control the Mini. I am very handy with electrical wiring, etc.

http://luxgeo.com/

(broken link removed to http://luxgeo.com/Wiring-guide.html)

The Mini's circuit board has a 2-screw terminal for stat connections. The Geo has your typical 10-screw terminals, typically used for HVAC applications.

I've read a ton of old postings about stat connections; they typically state that you connect the Rh & the W terminal to the stove's stat connections. What I don't understand is...where does power to run the electronic thermostat itself come from? Wouldn't the stat's "C" terminal require a 24v RETURN connection for internal power?

As I understand things, all the Mini's 2 termination points do, is allow a SWITCHED CIRCUIT to control combustion cycling, and DON'T supply power to the thermostat itself. Am I correct? If so, it would seem like I'd need to install at the stove, a 24v transformer for stat power, and a relay to provide a set of DRY CONTACTS to close the Mini's stat circuit to re-start the heating process. Or, did Enviro provide an on-board connection point for 24v available for powering the wall stat's electronics?

I emailed Lux directly and got a useless response. A second attempt at clarification was ignored.

If I am overthinking this whole process (I am not new to THAT concept!), can someone help set me straight?

Thanks

 

[DBCOOPER]

We are having an Enviro Mini installed in our porch within 2 weeks. My questions pertain to wiring a SMART thermostat to the stove. These are my requirements:

1) I do NOT want to rely on battery power to permanently power the thermostat.
2) I do NOT want to rely on wireless communications between stat & stove.
3) I DO want a constantly backlit display.

I'm leaning real hard towards a Lux Geo thermostat on the wall to control the Mini. I am very handy with electrical wiring, etc.

http://luxgeo.com/

(broken link removed to http://luxgeo.com/Wiring-guide.html)

The Mini's circuit board has a 2-screw terminal for stat connections. The Geo has your typical 10-screw terminals, typically used for HVAC applications.

I've read a ton of old postings about stat connections; they typically state that you connect the Rh & the W terminal to the stove's stat connections. What I don't understand is...where does power to run the electronic thermostat itself come from? Wouldn't the stat's "C" terminal require a 24v RETURN connection for internal power?

As I understand things, all the Mini's 2 termination points do, is allow a SWITCHED CIRCUIT to control combustion cycling, and DON'T supply power to the thermostat itself. Am I correct? If so, it would seem like I'd need to install at the stove, a 24v transformer for stat power, and a relay to provide a set of DRY CONTACTS to close the Mini's stat circuit to re-start the heating process. Or, did Enviro provide an on-board connection point for 24v available for powering the wall stat's electronics?

I emailed Lux directly and got a useless response. A second attempt at clarification was ignored.

If I am overthinking this whole process (I am not new to THAT concept!), can someone help set me straight?

Thanks

Yes you need a transformer and relay to do what you want it to do. Does that stat have a swing setting? If not you'll be unhappy with the stove short cycling.

 

[bubble]

Yes you need a transformer and relay to do what you want it to do. Does that stat have a swing setting? If not you'll be unhappy with the stove short cycling.

Hey DB, I like your avatar! I thought you jumped out of an AIRPLANE, not a copter, lol. And thanks for the reply.

Yes, this stat has the swing settings, adjustable +/- 2.25 degrees from setpoint.

I can definitely do the CONTROL circuitry, any pointers on exact components to get? I guess I can always peruse Amazon/eBay etc. Any clue if anyone's already done what I'm suggesting? And if so, where were they mounted? Any knowledge of any KIT containing these components?

 

[DBCOOPER]

I've gone pretty crazy with my control circuits. Will your exhaust have vertical rise or a straight horizontal?

 

[bubble]

The installer is suggesting 3' of rise or so...sounds logical to me, for natural draft. He's also concerned about the wall penetration being too close to the corner outside. A portion of my kitchen extends 24" from this vent opening. He says 12" is required from the coaxial pipe wall to the corner. I suggested a non-flammable barrier, lol. Ever heard of anyone doing that to reduce the 12" clearance requirement?

 

[DBCOOPER]

I didn't need to power my stat but I didn't want problems with power failures. I have a duplex receptical that I plug a cyberpower UPS into and it powers the stove. The other outlet I wired a plug with an SJ cord on it and power a time delay relay that opens the thermostat circuit on power failure. This puts the stove in shut down mode and won't let it restart until power has been restored for 10 minutes. This prevents the ups from exhausting its battery in conditions of long outages and allows an orderly shut down of the stove, which is important if I'm not home. I don't have any vertical rise on my stove and a power failure only needed to be expierienced once to know I had to do something to prevent it from happening again.

 

[bubble]

Well I installed the vent pipe today. Here's how it went. Tomorrow I shall get some pellets to test-drive this thing!