hi- it's now winter again, and i too have the same problem.
During the night when it gets below about -5 the alarm box on the outside of the house beeps every 1-2 minutes. To be honest, it beeps more the colder it gets.
When the sun finally gets on it and warms it up it stops(?).
Did you get yours sorted in January? I have rung the company that fitted mine to come and have a look at it, or if they know anything about any problems they might have with that model.
Hope to get it sorted soon as i do not wish to be awake from 4.45, and lord know what the neighbours are saying!
h
December 2010