I have a Heil NTG 3/FBF Furnace. My pilot light is not on. The fan will come on if I turn it on but with heat, but only cold air will blow. The pilot will not ignite all. I've tried cutting off power to the furnace and closing the gas valve and leaving it alone for 5 to 10 minutes. Then turning it back on with all the doors properly attached.

Check to see if the circuit board is flashing a blink code. If so look on the back side of the blower access door for meaning and post the results here.

Thank you for your help. The circuit board is not flashing a blink code nor does it have any type of led

Here are a few docs.

http://icpindexing.mqgroup.com/documents/086477/44111260106.pdf

http://icpindexing.mqgroup.com/documents/086477/44101260201.pdf

Both docs mention that you have a flame sensing type system. I cannot locate any other info on your furnace.

Depending upon your level of understanding of your furnace and it ignition system you might be able to check for some items.

First check the fuse that is on the circuit board and make sure it is good. See figure 11 on instructions

Next make sure all wiring to the board and pilot are tight.

Other than these items you will need electrical test equipment. It is a good possibility that the spark box as it is called might be defective not generating the spark needed to light the pilot. This is usually the case with these units along with defective flame safety controls.

Thank you again, I actually checked the fuse earlier and I found the documents online as well. I appreciate your taking the time to answer my questions.