Quote Originally Posted by bellavite1 View Post
So, if the issue is the hi-limit and I turn off the main switch and jump the wires bypassing the hi-limit the furnace should work?
I am pretty sure we tried yesterday and still no love.
Then , with the furnace working, it reached the programmed temp, turned itself off and tried again to restart even though theoretically it should have not, but this time although the igniter was glowing, no flame...Weird...That's why I am shooting for the CPU...I have a headache now...
You need to have someone come out and look at it.

Limit switches don't just go "bad". They go bad by continually being tripped. Boards are not very common to go bad either... The most common problem with boards is the blower relay built into them not turning the blower on.

Limits or any safety should never be bypassed unless for diagnostic purposes only...