I have a Lennox GCS29 unit that's at least 9 years old. The heat runs off natural gas. I turned it on a couple of weeks ago to make sure it would work since I spent $600 fixing it last winter. It came on and worked fine. Last night, it got a little cold in the house so I thought I would turn it on for a few. Turned it on and nothing happened. It never came on in the house. I went outside to see if the gas meter was running and nothing was going on. My dad came over to check it out and said he couldn't hear anything... no clicking like the igniter was trying to fire... could it be that the igniter has gone out?

Have someone at the furnace then turn it on and observe. You should here a small fan run then the ignitor should glow.

Okay, my dad went outside while I turned it on. On heat and auto, it will not cut on by itself. When I turn it in the ON position, it does cut on but only blows cold air and the gas meter does not run as in the dial is not turning.

This is a selfcontained unit, When you turn the unit to heat,the combustion fan should start,which vents out the top of the unit. It could be a number of things, you are better off hiring a pro on this one. If you own a voltage meter we could try walking you through a few things.