I have a fairly new amer std heritage 15 heat pump with a tcon803 stat. This is the first winter it has seen. Is it normal when in defrost mode to shut off when the indoor stat temp is satisfied? This has happened twice this cooling season. 99 % of the time it will totally complete the defrost cycle, the outdoor fan will restart and resume heating. Thanks for all the great advice and happy new year to all. Uncle V.