Back the springs off a turn or two then lock the set screws down.
Check the fins on the blower wheel. I had a Trane unit just let go of all the fins on the wheel and scattered them everywhere. Obviously, put...
Process of elimination.
What happens when you put a incandescent bulb in the fixture?
What happens when you put the LED in a normal lamp socket?
Completely off subject but, it sounds like this bedroom may not have a legal egress window size.
clean or replace the flame sensor. Might need to replace the sensor and ignitor as a single component.
I'm reading this as the OP wants to have two thermostats attached to one furnace.
While conceptually the same, the guts differ from maker to maker. Replace the entire assembly.
I have seen one instance where the inducer motor would run but, not fast enough to "make" the pressure switch.
Maybe some return air registers are...
Well that's not good. What happens if you prop the door open so the furnace can breath?
While the pin spread between T12 & T8 are the same, you can not put T8's in a T12 fixture and vice versa; with lasting results.
check for a blown inline fuse between the line power in the fixure and the ballast.
Yes, only one leg is switched and the fan will not run with just one leg.
The coil on the relay is responsible for pulling in the second leg to...
I have had a situation where the inducer blower motor is running just fine but, for whatever reason, over time it just wasn't getting enough...
Unfortunately, this is not a project where you will be able to save money by doing some work yourself.
The work you propose requires a permit and...
If you can get both ends removed, then just throw it away and replace it. Go with hard duct wherever possible, ideally from the dryer to the vent.
Separate names with a comma.