The frost must be removed. A heat pump has a cycle called a defrost cycle, which removes the frost from the outdoor coil. A heat pump unit will defrost regularly when frost conditions occur. The defrost cycle should be long enough to melt the ice, and short enough to be energy-efficient.Click to see full answer. Furthermore, how often should a heat pump defrost?A typical heat pump will go into defrost every 30, 60, or 90 minutes if the outdoor coil temperature stays below setpoint (~31° F). MacFarland’s system goes into defrost mode only when necessary.One may also ask, how long should heat pump defrost cycle last? A normal defrost cycle of a heat pump on average will only last for 5-15 minutes until it switches back. Considering this, why does my heat pump keep going into defrost mode? Defrost issues can be caused by faulty relays, controls, or sensors. There could also be a problem with the reverse valve that switches the unit from heat to air conditioning mode. Outdoor fan problem. The fan motor may be failing or completely dead.Should my heat pump run all the time?Most heat pumps will run constantly during the cold weather. This means that it is normal for your heat pump to be running constantly during winter when the temperatures are at or below 30 degrees. However, if the heat pump is running constantly in the cooling mode during the summer, then there could be a problem.