On Thursday evening I was going to attempt to change my filter, I took the 2 doors off the front of my Bryant Horizontal Furnace and was looking for filter. With no luck, I gave up and put the 2 front covers back on. Now the RED LED light is on, not flashing just continuously on.

What should I do? I turned off my thermostat because I was worried what was wrong or happening. However, it is getting quite cold in here.