Hi all - I'm in a house that I've owned for about a year now and went through last winter without a hitch with the heat pump, which is about 5 years old. This winter, starting in late December or early January, I started having problems. It's a Carrier heat pump, with the air handler inside and condenser unit (or whatever it's called) outside. I've always had natural gas forced-air and this is my first heat pump (side note - no matter how "good" they're supposed to be, heat pumps are absolute crap compared to gas forced-air systems).
Anyway, I noticed odd sounds one night and realized the next day that the fan motor (outside) was shutting off and then coming back on before the fan blade had even stopped spinning. Sometimes this will happen only occasionally, but at other times it will cycle on and off every few seconds, repeatedly. It's annoying, sure to damage the fan motor (if it's not already shot) and highly inefficient. It is a struggle to keep the inside temperature at 64 degrees now.
In briefly talking with an HVAC guy, he noted that heat pumps go into a defrost mode. That brings me to another important point - back in the Fall, when the thing was actually working properly, I could see that the outside unit was frosting up - it would then stop and defrost and re-start. Now, in the dead of winter, there is NEVER any frost on the outside of the unit. I mean not even the slightest hint. I've also noticed that the green light on the thermostat (indicating that electric heating elements are "on") is on much more often and almost constantly if I want to keep the temperature at what I now consider a "balmy" 66 degrees.
I'm going to call an HVAC tech. of course, but was wondering if anyone has encountered this problem or perhaps knows what it could be. Any advice or input is most welcome.