Lennox g8 furnace problems

[TonyOZ]

When i turn up thermostat for heat I hear the burners ignite but no blower comes on. I have to switch on the blower manually from thermostat.
I have checked the limit controls seem like they are operational. what else is next?

[HayZee518]

on your plenum is a fan control. looks like a metal box 3" wide X 4" long. take the cover off, you'll see a white knob. one position is auto run other is manual run. operate this to see if the fan turns on. try adjusting the set points on the rotating disk. this is your on-off band. if this doesn't do it, I'd say replace the control

[TonyOZ]

I looked for a control box with the white dial on the plenum and saw nothing.
The only thing on the plenum is the two limit switches. After digging around in the furnace now when I call for heat the burners won't even come on. Nor will the fan on manual or auto at the thermostat.

[TonyOZ]

I just tried to jump the fan post at the thermostat and got nothing. I am trying to work down the line.

[hvacwiz]

Did you put the blower door on correctly? if not the door switch might not be closed. If you have a circiut board in your furnace this is what controls your fan operation on a timer and this may be your problem.

[TonyOZ]

I think I figured it out. I messed around with the limit switches and found that the low/fan switch was missing the adjustment dial. I rotated the screw that the dial was on and heard a switch click. So I went to the thermostat and called for heat and th e burner came on, but I still have to turn the fan on manually. Basically I guess the limit switch needs replacing.
Thanks for the feedback.