[onefleshforlife]

Not sure the brand.. When I have the thermostat call for heat the vent blower and the blower both come on and there is no glow.. I have tested and bypassed the limit switches and that doesn't fix the problem. Now the diagnoses light flashes 4 times which is supposed to mean that there is an open limit switch ( so much for the diagnosis light ).. I did unplug one wire at a time going to each limit switch according to the wiring and tested each connection for voltage and I traced the voltage all the way to the high limit switch and lost voltage when I connected the output wire to the high limit switch. With the input wire is connected and the output wire disconnected I have 24 volts once I connect the output wire I lost voltage. Does that mean the board is bad?

[T-Top]

Are you checking voltage from common to each side of the limit switches?

[onefleshforlife]

Yes I am...

[eschuen]

Put a jumper across the high limit and see if the ignitor works

[onefleshforlife]

Thanks I tried that didn't work also tried jumping all switches all to no avail..

[T-Top]

Did you check to see if you have a 115v going to the glow coil after the inducer motor starts. Just making sure you don't have a hot surface ignitor burnt out and the furnace is out on flame failure. One more question, is the pressure switch closing after the inducer motor starts?

[onefleshforlife]

Thanks.. I have no voltage at the ignitor and the inducer is working fine and I also bypassed it with a jumper still nothing..

[T-Top]

Did the pressure switch close after the inducer motor started. At idle the pressure switch is open the inducer motor closes the pressure switch.

[onefleshforlife]

Yes it works fine However there is no voltage supplied to the inducer... If I jumped the inducer shouldn't it be the same as the inducer motor closing the switch..