On my Trane there are two lights-red & green. The green light blinks
relatively slow when there is no demand for heat and much faster when there
is a demand for heat. Normally, the red light blinks about every 20 sec or
so. When there is a problem it is the one that is used to interpert any
diagnostic codes. This is spelled out in the furnace manual. Suggest you
read yours or find it at the Trane site for more specific information.
MLD
"B" wrote in message
...
In my attic there's a Trane central heat/AC unit. There's a round "window"
the size of a quarter, and peering into that window I see a blinking red
light. Whats up with that?
-B