I have a Payne PF1MNC hvac, and just replaced my White Rodgers thermostat (It wasn't blowing hot air or kicking in in Auto mode) with a Hunter 44155C. There were 4 wires attached:

G to G
R to Rh (with jumper)
Y to Y1
W to W
And an unattached B

I attached them the same to the Hunter:

G to G
R to Rh (with jumper)
Y to Y1
W to W/B (the only option)
And left the B unattached

When I tested the operation, the fan blew hot air for several minutes before stopping, and hasn't worked since. I cannot get the fan to start in Heat or AC mode.

I have checked all circuit breakers in the house and on the outside of the HVAC.

What am I doing wrong? Is there a circuit breaker inside the HVAC, and if so where and how do I get to it? Or am I all messed up and need bigger help?

I have been surfing the forums, but have had no luck. Thanks in advance.

Should be right. Looks fine.

Check all connections to be sure no loose or missed wires.

To test the system disconnect the wires from the stat, and temporarily touch:

Red to green should start fan
Red to white should start heat
Yellow to white should start AC

If all works that way, then the stat is either not set right, or defective.

There are sometimes small fuses for the control (stat) circuit, on a board or at the transformer.

Tested the fan as suggested and it did not start. I'll investigate for fuses after work today, but curious as to what's wrong now.

There isn't too much to go wrong if the fan test failed. You either do not have power to the furnace or the controls. Note, If you had the cover off the furnace, you need to use you third hand to hold the safety switch in. Unless it is a heat pump, The outside unit has nothing to do with the heat or fan. Check the circuit breaker to the furnace. Turn it all the way to off and back on again. Check the control board for a fuse. The newer ones use an auto style blade one.

Thanks for the help, it was a circuit breaker in the garage that was tripped.

Problem now is: I reset the breaker, heater fan works fine, fan stops when temp reached, breaker trips again. Rinse and repeat...

What might cause this behavior?