Actually, I know I shorted it! I was installing a ritetemp therostat.

C-Blue
G-Green
Y-Yellow
W-White
R-Red

It seemed pretty straight forward.

Genius that I am, I didn't shut of circuit breaker.

When short occurred I looked at outside circuit board and nothing was tripped, I also looked at circuit breaker on blower.

What now?

Thanks

So what happened when you "shorted" the wires? Did you see a small spark at the wires?

This wiring is only 24 volts, and typically, the red is the feed, and all the others are switch legs back to furnace, fan , compressor.

Not sure what the blue is for. Sometimes, certain stats need a common, the return for the feed, for some option like a time clock in the stat. The only time you would have an actual short is if the red and common were to touch.This action would short out the 24 volt feed, and there may be a small fuse for this circuit, usually at the transformer, sometimes on a control board.

Otherwise, if you touched any other wires to the red, you would see a small spark due to sending power to a relay coil, which is normal, and simulated a switch closure, and not really a short circuit in the true sense.

Thanks for your oh so prompt response. I did see a small spark.

I did talk to the Ritetemp tech this a.m. their helpline opened at 9am est. He thinks I blew the 5 amp fuse at the furnace control box; so off to the attic I go in 98 degree weather. I couldn't have waited until the weather was 70 degrees. I guess I'll keep my day job as an airplane mechanic.

It appears you concur.

Thanks again.

A while back I was hooking up a new Honeywell thermostat to a new Heat Pump and miswired it due to crummy instructions from Honeywell. Labman, who used to be the resident thermostat guru on this site had me check for 24 volts from the transformer in the unit (red lead). I got zero, indicating a fried one. A new transformer cost me the princly sum of $11. Installed it, problem fixed. Good luck.