This mode switches the reversing valve, turns off the outdoor fan and heats the coil. In a matter of minutes the frost is melted and often steam will rise off the unit thus causing the smoking heat pump. We do not recommend covering the outdoor air conditioning unit. We do realize there are companies that make covers for winter use, but our experience has been that they actually do more harm than good. Every component in the unit is designed to handle all the normal elements.
Covering can actually trap moisture inside and cause mildue and corrosion.
If you must cover the unit during the Fall season to keep leaves out, just cover the top and partially down the sides. That depends on many different factors. On average, it is cheaper to operate a separate hot water tank. However, in colder climates with boilers that are set up to maintain a constant temperature, the opposite is true. With our new line of Energy Kinetics boilers you can save a significant amount of money by heating hot water with the boiler.