I'm having trouble with my garage door opener. On warm afternoons when
the sun is shining on the garage door, it won't close properly. It
goes down part way, then the light flashes and the door goes back up as
if there's a blockage in front of the infrared beams. I've checked for
something in the way, as well as the alignment of the beams. Early in
the morning and at night, it works perfectly. What is the heat of the
sun doing and how can I remedy it?

By the way, it's a 1/2 h.p. Craftsman and a metal rollaway door.

Thanks.

-Fleemo