Arcoaire LP, exhaust fan comes on, see glow in igniter area. Hear small click. No flame. Times out and then tries again.

Are you sure you are getting gas to the main valve? This is a fairly common occurrence when installing a new unit or gas line since there is too much air in the line. Make sure the gas is off, remove the cap on the drip leg and then slightly turn on the gas. If you can't smell or hear gas, you need to purge the line better. If you hear gas, I would still let it cycle a few more times. After that, could be a bad gas valve.