They're pretty automated for startup. I am assuming you have the same control as I do on my 3000DX. Turn the "Heat" control knob all the way up (completely clockwise). Press the rocker switch at the top of the switch to start the furnace. A yellow LED should light on the control panel and you should hear the furnace fans start to run. If the yellow LED blinks, supply voltage is low.
After a couple of minutes, the fans in the furnance should speed up. Within 2 minutes after the fan speed increase, the red LED should light indicating the furnance has started. If the furnace fails to light, the red LED will blink indicating the furnance has begun the shut down sequence. After a few minutes the furnace will stop ready for another start sequence.
It may take a couple of start sequences to get the furnace to start because the fuel
system my need to prime (the fuel
will self prime). Don't shut the furnace off by disconnecting power or damage to the heater will occur. If the furnace doesn't go through the startup sequence above the circuit board is probably defective.
To shut down the heater, move the rocker switch to the center (off) position. The heater will go through a shut down sequence and cool down. The red LED will blink during the shut down sequence.