# Milivolt thermostat on a pellet stove?



## MCPO (Jun 23, 2008)

I think this needs to be cleared up.
 Unless I missed something somewhere along the line researching stoves I can`t find any reference or need for any pellet stove to utilize a milivolt (powerpile) thermostat. To me it is redundant since there is 120v on board already and which can be stepped down easily and cheaply down to 12-24 volts. This method is much more dependable too.
 These milivolt thermostats utilize very low power vs standard 12-24v generic 2 wire low voltage type thermostats or most any programmable one that uses batteries to retain the settings memory.  Milivolts sytems are powered by a thermocouple (generates a milivoltage) heated by the pilot light usually found in  gas furnace conversion boilers for steam heated buildings.
 I see repeated references to purchasing a milivolt thermostat for a pellet stove and to my knowledge it will not work properly unless installed in a milivolt system.
 Of course I have been wrong before so there`s a slight chance that I might need to be enlightened. Please do.
 John


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## jtp10181 (Jun 23, 2008)

All the pellet stoves we sell use a millivolt system for the thermostat. Basically, the stat can't get power from the stove so if its programmable it needs a battery.


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## MCPO (Jun 23, 2008)

jtp10181 said:
			
		

> All the pellet stoves we sell use a millivolt system for the thermostat. Basically, the stat can't get power from the stove so if its programmable it needs a battery.


No where in my Harman manual is there a reference to a milivolt thermostat. It does however picture a typical White Rodgers 2 wire thermostat.
You might be selling the wrong item to at least some of your customers.. 
 Battery power used  in a programmable thermostat have nothing to do with the control circuit and are therefore isolated.
 The 1.5 - 3 volts provided by the batteries is specifically for the purpose to retain the memory for the program / settings . 

UPDATE:
OK, I did manage to find a White Rodgers programmable thermostat that will operate a either a MV system or a powered system up to 30 VAC so I must apologize for inferring you might be selling the wrong thermostat to some customers.
 But I have to question any need to use the milivolt connections.

 John


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## gw2kpro (Jun 23, 2008)

Giovanni said:
			
		

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My breckwell manual specifically stated that it required a millivolt thermostat.  It states "A millivolt thermostat is required. A fixed wall mount or
Breckwell’s hand held model can be used."

http://www.breckwell.com/database/P27002005Manual.pdf

I went to Home Depot, bought a programmable millivolt thermostat, hooked it to the stove, switched the stove to hi/lo thermostat setting, and it has run like a champ ever since.


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## MCPO (Jun 23, 2008)

gw2kpro said:
			
		

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 That`s good enough for me with regards to your Breckwell anyway. I won`t argue with the manual.
 Thanks , John


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## jtp10181 (Jun 23, 2008)

Giovanni said:
			
		

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We have two thermostats. The one that comes with the units which is a simple mercury switch stat and thus requires no power. The other is a pretty simple battery powered programmable stats which is sold by Quadrafire for Quad pellet stoves. It is mfg by some major stat mfg but I can't remember which one, I'm thinking honeywell. We are not selling the wrong thermostats.

What Harman unit do you have? I looked at a few manuals and they have room sensors, not thermostats.


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## GVA (Jun 24, 2008)

Hope this helps.
https://www.hearth.com/econtent/index.php/forums/viewthread/7790/


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## MCPO (Jun 24, 2008)

jtp10181 said:
			
		

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 I did apologize earlier for that remark. 
 My Harman P38 will connect to a thermostat.
 Thanks for the info.
 John


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## ylomnstr (Jun 24, 2008)

So do we really have an answer here?  Is millivolt needed?  I believe my st. croix is prewired, and the back of the unit has a red and black connector for the tstat.  My old quadrafire came with a basic mercury based tstat where I hooked up the black wire to the black connecter on the back of the stove, and the red to the red.  Easy enough.  In my new house, i'm trying to go wireless, and with something with a programable setting.  I dont think home depot or lowes sell a wireless tstat from what I found. I'm just trying to avoid running wires through my attic and walls.  What are our options?


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## MCPO (Jun 24, 2008)

ylomnstr said:
			
		

> So do we really have an answer here?  Is millivolt needed?  I believe my st. croix is prewired, and the back of the unit has a red and black connector for the tstat.  My old quadrafire came with a basic mercury based tstat where I hooked up the black wire to the black connecter on the back of the stove, and the red to the red.  Easy enough.  In my new house, i'm trying to go wireless, and with something with a programable setting.  I dont think home depot or lowes sell a wireless tstat from what I found. I'm just trying to avoid running wires through my attic and walls.  What are our options?



What I`ve learned here was to trust the stove specific manual. I`ve been informed that at least one Breckwell pellet burner requires a milivolt thermostat as stated in their users manual.
 John


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## jtp10181 (Jun 24, 2008)

All pellet stoves I have seen will not supply power to a thermostat. So if you plugged in a standard furnace programmable stat it would be dead since those get power from the furnace itself. Now I have not had experience with every pellet stove out there so some might run 12 or 24v through the stat wires.


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## stoveguy2esw (Jun 25, 2008)

ESW units use a millivolt system as well.

essentially ours works as an "open circuit/ closed circuit" system , when open the stove banks, when closed , the stove reverts to desired heat range.


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## I love cheap heat (Jun 25, 2008)

Like I mentioned in another post, the T-stat is a basic switch. If you take the T-stat two wires and twist them together , the control board will "sense" the thermostat is calling for heat and advance to a higher setting. So any T-stat that, line voltage, low voltage or Millivolt, that simply opens and closes a connection between the two wires will work on most pellet stoves.


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## concep78 (Dec 2, 2008)

i purches a skytech 5301 wireless thermostat wich is a milivolt thermostat i hook it to my lennox montage wich is a 24vac thermostat. the skytech 5301 will start the pellet stove but it won't shut it down, do i have to connect this thermostat difrently or this thermostat don't work for these stove i know this is a very stupid question but i am desperate ..  please  helpppppppppppp.  

thanks 
Felipe
NP AK


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