I'm not sure. I'm guessing based on what it's doing. I think it's either the sail switch or the control board. Here's what it's doing:
When we ask for heat, the blower starts and runs for about 10-30 seconds (sometimes long, sometimes short) and we hear no igniter clicking. Then it stops.
Sometimes, when we ask for heat, it works as expected. The blower runs for a few seconds and then we hear the igniter and the burner go - and we get heat.
It seemed that when it wouldn't light, we could turn it off (via the iN-Command system) for a minute or two, and then try it again and it might work. On our last night, however, it would not light at all - all night
I found I don't have all I need to cut/extend the wires, so I'll need to order some stuff- and I want to have the parts before I start cutting if possible.
By the way, I think the manufacturer's warranty on this furnace is only 2 years. Is that right? We're even beyond 3 years anyway, so I'm pretty sure there is no warranty.