My trane XE90 wasn't giving out hot heat but warm/cool heat and the furnace light was flashing 2 lights which meant "Systems Lockout." I turned the thermostate off and the furnace switch off and let it sit for 30 min and then turned both back on. Now light is flashing constant. The control panel says flashing slow is okay flashing fast I need to "Call for Heat." What is fast and what is slow, I've never paid any attention to the light before so I don't know what fast or slow is on this thing. Is slow every couple seconds or continuous? By the way the heat after being on now for 15 minutes is warm/hot, but light is still flashing. I'm trying to figure this out without calling someone for help...