I am having a problem with my Olsen Ultramax furnace (installed early 90's). Furnace will ignite but within a few minutes shut down although blower fan continues to operate continually blowing cold air. Fault light in furnace stays on steady and indicates control needs to be replaced according to chart inside. My questions are..... Is fault light a reliable way to diagnose problem with furnace? Is there a possibility that there are other components contributing to the problem? If it is only the control, is this something I can change myself as it looks fairly easy. Control is a White Rodgers 50A50-216.......Thanks Richard.

Should have also asked... are there any tricks for getting it working for tonight.

 

Welcome to the forums.

Try cleaning the flame sensor rod. It will be a metal rod attached to the furnace with a one screw bracket and a single wire. Remove it and clean it with a scotch brite pad or steel wool. It needs to be very shiny.

Also, make sure you have a clean air filter in place. Make sure too many registers aren't closed off and that the return grille(s) aren't blocked.

Other than that..... if the red light comes on solid.... it does indicate a problem with the control board.