We have an Arcoaire heat pump (2.5 ton--YC030G)/electric furnace system that is about 10 years old. We had no problems at all until this fall. When we turned the thermostat to heat, it ran for one cycle and stopped. After that it wouldn't do anything. A technician came to fix the unit and replaced a burned up transformer on the furnace unit and a defrost control board on the heat pump unit outside. The unit then came on and ran one cycle, then wouldn't come on again. The transformer was burned out again. The technician then replaced the transformer sequencer and left the outside unit unwired, saying that it had a short in it. Since then we have used the electric furnace by itself and are going to replace the outside unit. Any idea what may be wrong with the heat pump unit and what the best course of action would be? I hate to buy another unit and run into the same problem if it lies somewhere else.