Any heating and cooling Guys out there? I have a question

67Dart273 is right about the flame sensor. They are very sensitive. Most HVAC trained professionals will frown on sanding the sensor. If you clean it with anything, use a soft piece of paper, like 600 or better yet, a coarse scotch brite pad until it is bright without discoloration.

This is only a band-aid. If the sensor is fouled, it should be replaced. You can clean it to get you by, until you have replaced it.

I was not able to find the diagram for your model online, but some models have a trouble code from the LED light on the PCB panel, down below. You should be able to see the LED through the sight glass, if this is the case. Do not take the door off to read the light. Just pay attention to the series of flashes and relate them to the legend that came with the furnace manual or legend label somewhere on the furnace, usually on the door.

If you can't see the light, if the sight glass needs cleaned, you can remove the door and clean inside and get the thermostat to call the furnace again, to instigate the trouble code cycle light.

If you do not have a legend for the codes flashing, or you do not have a code flashing on the LED light, you can still diagnose the problem, but the first thing you need to do is clean everything.

Pull the burner assembly out, blow it off, vacuum it, wipe it down, vacuum out everything inside. Replace your filter (this will affect other things, including other sensors that can short cycle your furnace) and try it all again.

There are carbon monoxide detectors, also known as flame roll out sensors, these will also detect any orange flames being emitted, even in short bursts, from dirty burner assemblies. You can't properly clean a burner without removing it.

Clean everything first, try replacing the flame rod sensor. if that does not fix it, test the exhaust pressure switch by disconnecting the hose while it is running to see if it immediately shuts the burner off (and possibly the blower and exhaust motors).

You might also want to check your exhaust chimney to see if it is even partially blocked. Lint buildup or birds nests, snow, etc., can cause the pressure switch to do what it's supposed to do, which is tell the system to shut down, sometimes this happens once the ignition is proven and you have flame.

Your best friend is going to be the LED code flashing. If you open that door to watch it, instead of using the sight glass, it will reset the computer and has no memory, so you will need to turn the thermostat up/ on again to call the furnace on, again, before diagnosing it. There is a switch on the access door that is tripped, that turns the computer and the system off, when the door is off/ open.