I have a Lennox Whisperheat gas furnace model no. G20Q3/4E-125-2. On normal start up the pilot would light and then there would be a click click click noise several times then the burner would light and the blower would kick on. Now what is happening is the pilot lights and then the clicking starts clicking super fast, the burner never lights but the blower kicks on. No heat! Any ideas? Thanks!

You may have a dirty pilot orifice and its not hitting the flame sensor to tell the main burners to kick on. On some furnaces the blower will come on 90 sec. after the thermostat calls for heat even if the main burners are not on.

When its clicking and the pilot is lit check for 24v on the main valve terminal on the control module. I was able to jump my furnace by connecting a wire to the main valve terminal and touching it to the ths terminal on the module. You only have to hold the two together for a few seconds and the main valve will stay lit and burning. I have replaced the control module on my furnace twice with no luck either time. I also read some negative feedback on the gas valves. The pilot and main valve have been known to both open at the same time. There has also been bad reports on the johnson control module and honeywell control module. I am still trying to get my hunk of junk whisperheat to work right myself and the bad part is I am a HVAC technician and never came acroos a furnace problem like this before.

Make sure the ignitor is arching to the flame rod. I came across a whisper heat that the pilot would light but not the main valve. The problem was that the flame sensor rod was picking up extra current off the pilot ignitor and kept the main valve opening. I just bent the flame rod away from the ignitor. These furnaces have been vary trouble some. I have been called to four of these furnaces and they all had the same problem now.