The red light on my Trane XR80 furnace continuously blinks. I never noticed it before, but the heater seems to be working OK. I cleaned the filter about 3 weeks ago. I looked inside the door but it says heat Call and No heat call? Is this normal?

My trane XR80 furnace cuts off after a few seconds, but the red light constantly blinks what does that mean. Thank you

I have a Trane XR80 but a have a steady red light blinking and turns off every now and then but, when it starts up again I can hear a high pitch sound.