I have a Bryant+90 installed in 2000. I've had to request several service calls for various problems, but the most aggravating occurs when the furnace fails to come on. The thermostat might be set at 65, but, the temp shows 60 degrees... and no furnace on! Solution (temp.) is to turn off switch next to furnace, wait a couple of seconds, then turn back on.
Problem used to be more sporadic, but with the colder weather it seems like it's almost a daily occurrence. Had a repairman here yesterday... and this morning... furnace failed to come on. I've been told to not shut off registers to unused rooms, to not use programmable thermostat... this is NUTS! Advice??

I've been told to not shut off registers to unused rooms, to not use programmable thermostat..... this is NUTS! Advice???

Not nuts advice but if you shut off to many registers the furnace can trip on the high temperature safety limit and then you will have to reset the control like you are doing. The furnace was designed to move so much air over the heat exchanger and when you cut off registers or have a dirty air filter you stop the movement of some of that air and then bingo the furnace has problems.

The thermostat settings should not make a difference. If the thermostat is calling for heat then the heat should come on.

I did follow repairman's advice about not closing off registers (I only had one closed off) yet, the furnace still failed to maintain heat this morning (failed to come on).

If this is a furnace with PVC pipes pull the front door at the top toward you and then lift it up out of the way. There is a small plastic window about the size of a 50 cent piece down on the blower compartment panel(bottom half of the furnace not the burner window on top similar in size). You will see a small light in there. If the furnace is not working it will flash a code. Usually rapid flashes followed by long flashes on the newer models. Count each. 3 fast and 2 long for example would be code 32. Turn the door over that you removed and you will find the sticker with this information. It will has several causes listed. It gives you a starting point to troubleshoot.