Thermostat Hookup

Hi,

My thermostat has
B O G Y W R RC

My Furnace has

C G R W Y TWIN

Right now They are hooked up with (first letter Thermostat, last one is furnace)

B -> G
G -> C
Y -> Y
W-> W
R-> R

All other not hooked. (Note I also do not have AC)

I'll start by saying EVERYTHING works except the fan is ALWAYS on, even when I put fan on AUTO in thermostat.

So I thought it must be because G is not hooked to G (For fan control).

So I switch G->G and B->C (reading that B was common on older stuff).

BAM my 5A fuse breaks.

I think okay, maybe B isn't common so I just hook G-> G and disconnect B AND C.

Okay now my furnace ignites, but the FAN will not turn on. So my question is what am I doing wrong? And why the heck does this actually work in its current configuration? Thanks

 

G must go to G.

G is fan control for A/C and FAN ON mode.

 

I tried hooking G-> G and hooking my Thermostat B to Furnace C

I had a blowup of 5A fuse.

My next step was to not hookup Thermostat b nor Furnace C, and just leave G-> G

THis time my furnace ignites, but I feel NO AIR coming from my vents.

SO i then hook Thermostat G -> Furnace C and Thermostat B to Furnace G,

Now i get hot air. What am I doing wrong? WHy and how is this working in the current configuration. Can someone explain to me? Thanks!

I really want my fan to turn on/off as needed instead of constantly being on blowing air even when thermostat is set to AUTO and not giving heat.

 

C does not get wired to the thermostat.

 

That's actually really good to know. So if C doesn't get wired to the thermostat, I wire G->G, it seems like there is no air coming from the vents. Am I missing something?

 

The fan on a GAS furnace should turn on 45 - 90 sec. after the burner starts. An electric furnace needs to be controlled by the thermostat. SO on an E furnace the thermostat needs to be setup to control an electric furnace.

Does the fan turn on if you switch the fan to on at the thermostat?