[silverstrk65]

Hello everyone. I replaced my oil furnace this past fall with a Traeger GBU130 pellet furnace. I installed the furnace but left the central air thermostat wiring unhooked. Now it's getting to be summer here in Wisconsin so I'm trying to get the unit working. Cannot find any schematics anywhere and had a sales person tell me the furnace doesn't have a "tie in" option so I'll have to set up the a/c as a stand alone system. I'm not sure if I find this accurate. The main wiring has not been touched. I'm looking to just know where the smaller wires for the thermostat go. With the new traeger there's only 2 wires used. Any help would be amazing before I have to call a technician in.

 

[yuri]

Yep. I found the install manual for it and it has no AC provisions. Probably because a lot are used in rural areas where people don't use AC because they open windows and it is breezy.

It has its own circuit board and built in 24 volt power supply.

You need a fan control relay like a WR 8A04 and a tech who knows how to wire it in. Looks like you will also need a 24 volt transformer to supply power to the relay and AC.



http://www.supplyhouse.com/White-Rodgers-8A04-1-Enclosed-Relay-24-VAC-Coil-Voltage-SPDT-14871000-p

 

[BayouRunner]

Couldn't you wire it up with a standard thermostat and take the r to ex jumper off and install a 24 volt transformer in the condensor control box? That is if it has a blower only option

 

[BayouRunner]

Sorry spell check got me and I can't seem to edit my post. Remove the r to rc jumper

 

[yuri]

I looked at the wiring diagram and it has a special control board with a built in transformer. No way to know what is R and there is no C external.

I would use a 8A04 relay and 40 va 24 volt transformer and mount them on the furnace. Y from the tstat can energize the AC and fan relay and yer golden. Would have to make sure the heat never got turned on at the same time, I would empty the hopper. Or you could isolate R and RC and run both thru the same thermostat and be 100% safe.

 

[user_12345a]

Check the blower cfm, hp, static pressure ratings. There should be a fan performance chart in the literature.

Need 400 cfm per ton at 0.5" or greater static.

If the fan is only 1/8 hp or something with a small blower wheel it won't cut it for a/c, the coil will freeze.

The heat from the pellet furnace could also melt the condensate pan on the coil if it's plastic.

 

[user_12345a]

In the manual "switching voltage is 9 volts"

With an a/c thermostat u'll have to disconnect the jumper between R and Rc or the 9v controls could get fried.

Appears to be 1/2hp so blower should be okay for most a/cs.

Fan center must be wired in right to avoid damage to both the blower motor and heating control circuits, limit operation should be verified.

Fan center:

They used to be used all the time to add a/c to old furnaces. New ones (not so new actually - anything made in the last 22+ years)have the relay built in to the board.

 

[silverstrk65]

Thanks everyone for all the info!! I went and looked at my old oil furnace(I saved it for some reason) and seen this....is this a fan center/transformer? Maybe it's what I need? I have no issues buying a new setup and have a friend to wire it for me but I'm a DIYer so naturally I want to do this myself.

 

[silverstrk65]

The thermostat wires were connected to the terminals and did take a picture in case I needed to hook it back up but something happened with my phone that the photos were lost.

 

[yuri]

Now that I think of it I was slightly wrong.:wink2:

What you need is a Honeywell R8222D relay.

You need a relay with 2 sets of contacts for the fan motor.

1 normally closed set will tie into the wire for the heat speed of the stove and the other normally open set of lower contacts will be used to tie into a high speed wire from the motor to be used for AC.

Then you hookup the normally open contact straight to 120 volts and the 24 volt coil of the R8222D to the Y or G wire for the AC from the thermostat. You also will need a 24 volt 40va 120 to 24 volt transformer to supply 24 volts to the thermostat and AC.

The problem is your current old oil relay only has 3 wires for the fan relay and the power for the stove heat speed needs to be isolated as it has its own source from the stove circuit board. That relay is designed to be used with a furnace which shares the 120 volts from line or thru the limit control.

You can pull the cover off the fan relay on the oil one and if it has a extra set of contacts like the R8222D then you can use it. I doubt it as there was no need for it. On your oil relay you have 2 wires for the transformer and usually a hot and normally open and normally closed for the fan. Problem is the hot is supplied common to those speeds and needs to be isolated.


https://www.amazon.ca/Honeywell-R8222D1014-General-Purpose-Relay/dp/B00097BDUA

 

[silverstrk65]

Went to my local heating/cooling place and got the parts recommended and its working fine. Thanks again guys!!! Couldn't have got it done without you.

 

[yuri]

Really????

I thought I would be walking you thru it for 30 more posts.:smile:

That was easy. Those were fairly complex instructions I gave you and some techs don't even know how to do that procedure.

Glad You could follow them. You must have some elec experience.:biggrin2: