A heat pump is an electric powered piece of equipment that both heats and cools your home. In the summer, a heat pump is no different than an air conditioner. In the winter, a heat pump operates in reverse and heats the indoors.
Heat pumps need auxiliary heat (electric heat or gas furnace) to help them when it is very cold (i.e. below 42 degrees) or when the thermostat is moved more than 2 – 3 degrees at a time.
The initial investment for a heat pump is higher than for an air conditioner, and the ductwork must be exactly right for proper operation. One common complaint of a heat pump is that the air coming out of the registers is not hot enough (compared to a gas furnace).
With all their drawbacks, heat pumps will reduce the winter heating bills. However, the savings compared to heating with gas is dramatic, and you will probably want to stay with a heat pump.