I have a clicking noise that is coming from my lennox gas furnace. When I turn it on the fan starts and then I hear a click and then a double click starts and won't stop until it attempts to recycle of which the same thing happens again...

The only thing out of the ordinary is that we left the garage door open last night. It got down to about 28 last night.. Is it too cold for it to run?

Got it working... must have been too cold.. took a hair drier and warmed up the circuit board for a little while and then restarted and bingo.. it started.

Some gas valves have a temp of operation level usually posted on the manufactures site or the valve itself.