Question about part for wood furnace.

[ttopmustanggt88]

Ive posted about a furnace i recently purchased and it did not come with all the parts like the blowers and electrical stuff but it did come with this thingy and i believe its the thermostatic switch for the main blower as it fits in a hole in the side of the stove but im not positive and if it is how would i go about wiring it up correctly? thanks for any imput. josh

 

[ericjeeper]

Commonly called a snap disc.,

or a thermal disc. It will wire between your hot(either from switch or stat.) and the blower.
Using a three position switch you can either use this to control off and on.. Or you can have an off.. or you can have an on. by overriding the disc

 

[mga]

always wire the black wire to a switch, or, as in your case, to that thermal disc.

never the white wire.

 

[ttopmustanggt88]

ok so i can go from hot power (black) to one side of switch, then hot black on the other side of switch to the hot black side of blower. and run white directly to blower and that should do it?? what kind of temps do these things normally turn on at?? thanks so much for the info. josh

 

[ttopmustanggt88]

there is a hole on the side of the stove that the switch fits in and the numbers on the back are kinda funny heres whats on the back.

312328
T-O-D
8226
L190-20

 

[Ken05]

That should be a 190f switch which seems a little high for a blower switch.It could also be a high limit switch to kill the draft inducing blower in an over temp situation depending on the furnace design and switch placement. Run a test light through it and see if it is closed a room temp - if its closed at room temp it is a limit switch - if it is open at room temp it is an operating switch. Heat it up with a candle and see if it closes at temp.
That furnace should have a model tag on it - call the mfg and get some instructions. It sucks to burn your house down.

 

[ttopmustanggt88]

thanks for posting that ken that just made my whole day make sense. couldnt figure out why this thing was closed at room temp, thought i had a bad switch but now it makes sense this is a limit switch for the forced draft. now i have to find where i can get a thermostatic switch for my main blower one that comes on at 140 and off at 90 or whatever they are. i have instructions but they are for a firechief and this is a granny. does anyone know where i can buy parts for a firechief?? thanks for all the help. josh

 

[mga]

ok so i can go from hot power (black) to one side of switch, then hot black on the other side of switch to the hot black side of blower. and run white directly to blower and that should do it?? what kind of temps do these things normally turn on at?? thanks so much for the info. josh

basically.....yes, that's the way to wire it.

 

[reaperman]

The thermostat switch on my firechief is a honeywell switch.

I took some numbers off of it. L4064A1339 6 0523H 2amps @ 24v AC

If you can figure out what those mean. I'd think most any switch would work, do a search on honeywell limit switches I know they make a ton of different ones, but they mostly do the same thing. Good luck

 

[Ken05]

This is the one I put on the plenum of my furnace. I wired it in series with a t-stat up on the main floor. You can see it is set for the fan to come on at 100 f with a 50f differential. With three 1/4 rounds of ash in the furnace I can hold the house at 72f for about 7 hours when it is 25f out.
Your local wholesale plumbing shop should have it on the shelf.

 

[timbrjackrussel]

Wiring?

Your thermostat up stairs would normally be wired in series with the draft control motor or fan or contol relay primary with a plenum high N.C. limit about 190F wired in series with the low voltage control transformer primary black wire, not the plenum fan motor. The plenum fan should be able to start any time the plenum gets up to about 180F and shut off at about 140F. What is the GREEN wire? It should ONLY be used as a bonding , ground .

 

[mga]

The thermostat switch on my firechief is a honeywell switch.

I took some numbers off of it. L4064A1339 6 0523H 2amps @ 24v AC
If you can figure out what those mean. I'd think most any switch would work, do a search on honeywell limit switches I know they make a ton of different ones, but they mostly do the same thing. Good luck

yours runs off a 24 volt transformer.

this is a good point to bring up because this wasn't mentioned before. he should investigate if his thermal switch is rated for 24 volts before doing any wiring.

 

[reaperman]

mga

I'm glad you caught this, I 'm ignorant when it comes to electrical details.

Here are a couple of pics of what mine looks like, the thermostat is on the very top and the conduit is running to the transformer.

 

[mga]

bottom picture......

to the right is your 24 volt transformer, and to the left of that is a relay. the relay might turn on the 110 volt blower.

hey....no cover for that stuff? lol

this is what he needs to investigate: whether or not his controls run off low voltage or high. (i'm willing to bet low, but i could also be wrong...lol)

 

[ttopmustanggt88]

alright i know im a noob but i have no controls. the only thing i have is a used squirrel cage blower and a limit switch that turns whatever i have on it off at 190 which needs to be my draft blower which i dont have. now im hunting for a affordable limit switch for the main fan. all those honeywell deals are 60 to 70 bux . then when i get that ironed out i need to find info on the draft fans for the firechief and try to locate one of those then i need to start on the ductwork side of the system. i know i feel like i got in over my head but im making progress its just slow. at least i have the flu and chimney installed and all to spec! thanks again for all the help. josh

 

[mga]

ya know what? i was looking at one of them and they said they have a "thermostatically controlled draft"....i read that here at the bottom of the page:

http://www.h2oasisinc.com/Fire Chief Wood Add ons/135/

i wonder now if that's what that does.........i gotta look into this more.

hey...brainstorming is how to solve problems...and lord only knows, forums are the best place for brainstorming.....lol

 

[ttopmustanggt88]

from what i understand i will wire a thermostat from in the house to the forced draft blower but with that 190 limit switch in line with it so that it will force a draft when the house demands more heat but yet when the plenum hits 190 the limit switch will shut off the blower and then the main blower will run off a different limit switch to turn on at whatever temp and off at another lower temp say 140 on and 90 off? thats how i understand this is designed to work. but now i just gotta find the parts and pieces as the only thing i have is the main blower and the 190 shut off limit switch. thanks. josh

 

[mga]

from what i understand i will wire a thermostat from in the house to the forced draft blower but with that 190 limit switch in line with it so that it will force a draft when the house demands more heat

ok, if that be the case, then that switch may be for a 24 volt line, since i doubt your thermostats are line voltage.

but yet when the plenum hits 190 the limit switch will shut off the blower and then the main blower will run off a different limit switch to turn on at whatever temp and off at another lower temp say 140 on and 90 off? thats how i understand this is designed to work. but now i just gotta find the parts and pieces as the only thing i have is the main blower and the 190 shut off limit switch. thanks. josh

it should work that way...you're on the right track.

 

[timbrjackrussel]

alright i know im a noob but i have no controls. the only thing i have is a used squirrel cage blower and a limit switch that turns whatever i have on it off at 190 which needs to be my draft blower which i dont have. now im hunting for a affordable limit switch for the main fan. all those honeywell deals are 60 to 70 bux . then when i get that ironed out i need to find info on the draft fans for the firechief and try to locate one of those then i need to start on the ductwork side of the system. i know i feel like i got in over my head but im making progress its just slow. at least i have the flu and chimney installed and all to spec! thanks again for all the help. josh

Check out a HVAC installer they may have taken an old gas or oil hot air furnace out. It should have a plenum contol for your blower complete. Check inside the old furnace for a schematic diagram to get an idea as to how it should be wired.

 

[Ken05]

Your thermostat up stairs would normally be wired in series with the draft control motor or fan or contol relay primary with a plenum high N.C. limit about 190F wired in series with the low voltage control transformer primary black wire, not the plenum fan motor. The plenum fan should be able to start any time the plenum gets up to about 180F and shut off at about 140F. What is the GREEN wire? It should ONLY be used as a bonding , ground .

My setup has no draft inducing blower or limit switch. The two controls only operate a blower relay in the oil furnace. The oil furnace's blower serves as the plenum fan. The draft control is an adjustable bi-metal damper circa 1950's.This setup works fine with no power. I only added the controls to increase efficiency and to better circulate heat on the main floor.
When the wires outside blow down my house stays toasty warm without needing to fire up the generator.
I didn't give a crap what color the wire is it only 24vac and runs 4 feet. Plus the blower almost never runs as this system uses natural draft for combustion and convection for circulation.Thankyou timberjackrussel for your concern.

No burning of OPEC juice was required to heat my home this winter.