Gas Furnace Problem

I have a Lennox G20 Whisperheat. Its about 6 years old and has just developed this problem within the last few days. The problem is sometimes the pilot will not light. When its not working there will be one loud click but the pilot will not light, then a few minutes later the fan turns on, blowing air. It will light if you turn the system off for about 5 minutes then turn it back on. A green light on the intermittent pilot blinks on and off when its not working. We have blown compressed air on everything, and the filter is clean. Any ideas what it might be?

 

cas1094:
The first place to start is with a complete servicing.


http://www.growinglifestyle.com/article/s0/a111199.html

 

spark or hot surface ignition? if it is a spark, remove the wire from the board leading to the sparker itself. if is is not a spade connector, and merley a flat wire end, cut one inch off an re install it into the board. this is a common problem, not sure if it is your model