Old rheem thermostat change out

[tiny tim]

I'm replacing the old round Honeywell t-stat on a rheem gas furnace. There is a data label with the model#-RGLA-100C-ER (made in 1989), but there is no wiring diagram. I ran new t-stat cable with 5 wires instead of the old 4 wire so I wouldn't need batteries. The t-stat is a non-programable, 1-heat/1-cool. It is set to gas and I left the RH/RC jumper in place. The problem is that when I connect power to the unit, the blower comes on even if the t-stat is off. I found out that the fan relay is normally closed and needs power to open. Is it possible to hook up a digital t-stat to this old furnace to meet that condition? Any help would be greatly appreciated.   

[Admin]

I don't think the fan relay is normally closed.  If you removed all the low voltage wiring from the furnace that would mean the fan would still run.  Did the fan run all the time with the old thermostat?

Is there an old fan/limit control (silver box) inside the furnace?  It may be stuck and if you adjust the fan on or off dial it should stop.

Or is there an HRV that may be interlocked with the furnace?  Turn the HRV off if so and the fan should stop.

If you can post pics of the thermostat and furnace wiring that would help.  Sometimes people wired R and G to a switch at the furnace in order to run the fan continuously.  Make sure there is not one installed in the on position.

[tiny tim]

I also thought the fan relay should be normally open. I tried moving the pointers on the fan/limit switch, but it didn't help. There is not a switch wired to R and G. Also there isn't an HRV.
I'm having trouble inserting photos from my thumb drive. What is the best method for getting images on this forum?
Do you know a good website for finding old wiring diagrams? I've searched for quite a while, but haven't found the right one.