The burners to my Day & Night Gas furnace will not ignite. I hear a clicking noise and pilot turns on but the burners will not ignite. I can turn the thermostat to on and the blower works??

I have exactly the same problem. I've removed the mount screws to the igniter (the small firing unit underneath the gas jets in the top half of that unit) and I can see the spark arc'ing across the firing node. So I know what is making the tick tick tick noise, but no gas gets fired.

I'm working on mine today (new years day). If I come up w/ an answer, I'll try to remember to come back and post and answer.

Wow,, no one answered this... Must have been a cold Winter...
No really, the flame detector appears to be defective. It is not sensing the flame from the pilot and the main gas valve won't open.
I hope you had it fixed!!

Ok, I forgot to answer back. I did find the solution. (now let's see if I can remember what it was). I had put in a new thermostat and connected I believe it was the "C" wire, which is optional. After double checking some voltages across various points to the system, I found that it was too high. Not being a H&C guy, I didn't know if a volt and a half was too high or w/in spec. When I mentioned it to my buddy Peter who IS an H&C guy, he asked me if I hooked up the "C" wire by mistake. He said that provides power to the system and is not needed in most cases. I came home, disconnected the "C" wire and BAM it fired.

Groovy.
p.s. I'm saying all this from memory. It on my new thermostat it said the "C" wire was optional. I think it was "C" it could have been another letter. Whatever it was, the manual DID say it was optional. So my advice is to go back over your connections and see if you have too many wires hooked up.