Hi,
Current Equipment:
Furnace: Trane BLD068L936, heating only
Thermostat: Honeywell T8085A

Last night I was going to change my thermostat to a Honeywell RTH230B. I have 3 wires coming out of the wall (1) Red, (1) White and (1) Green. I placed the red wire in the Rh connector and kept the jumper in place between the Rh and Rc connectors. I placed the white wire in the W connector and the green wire in the G connection. I followed the rest of the installation instructions but couldn't get the furnace to fire up.

I then reinstalled my old thermostat connecting the Red wire to both the R and C terminals, as it was before and the White to W and the Green to G. Closed it, turned up the temperature and nothing.

I've turned off the power to the furnace at the house circuit breaker panel, turned off the gas and let them sit off for 1/2 hour. Turned them on closed the cabinet and still nothing. The unit just doesn't seem to be getting any electricity.

Any help would be appreciated. Thank you for reading.
NWBRUIN

Try this: first, jumper the red and white wires together and see if the furnace runs. If not, locate the low-voltage terminals where the t-stat wires connect to the furnace. Remove the red and white wires and place a jumper across the terminals you removed them from. Try heating again, post results.

Thanks for the quick response. I tried what you suggested and still nothing. I'm pretty sure I blew the transformer. Looks like the green wire coming out of my wall was not for the fan but was the power (24v) source for my old thermostat's clock. Unfortunetly I didn't turn off the power when I changed the thermostats and my furnace doesn't have anything to blow, except the transformer, like a fuse. Any suggestions on where to get a decent price on a new one and what the replacement part number would be.
Thanks,
NWBRUIN

Happens to the best of us, until we learn better

Most transformers are universal,, 120 steps down to 24 volt for gas furnace
230 volts steps down to 24 volt for a electric furnace,, sometimes the might mount a little different

Depends on where you have to buy the transformer, but at a Home Depot it should be $15 - $20 if they have what you need.

Thanks for all the help. I got 3 quotes today from local shops over the phone and they averaged $150.00 for the part installed. If I can find the right part at Home Depot is this something I could do on my own. I will of course turn off the juice first!
NWBRUIN

Yes you can do it yourself if you follow the instructions, and read the information on the new transformer because it will probably not be exactly like the one you take off.
But if you get hung up someone here will help you.