Duh - Problem with new Suburban furnace not Atwood

As a last resort, have tech replace circuit board. I had problems w/furnace for 7 yrs, replaced all switches, etc. Tech said circuit board checks out OK, but what else could it be? He put in new circuit board and works as it should now.

For 7 years, the furnace was weird; worked, but not as I thought it should --- wouldn't come on when it should, cut off at wrong times, etc. It worked just enough that me and the techs thought it was just me, an old man who is clueless. Right, but wrong, eventually.