True or False: Frost on the outdoor coil is normal in heating mode.

In heating mode, it is common for frost to form on the outdoor coil of a heat pump. This is primarily due to the fact that the heat pump is extracting heat from the outside air, which can result in the coil temperature dropping below freezing, especially in cold, humid conditions. The moisture in the air then condenses on the coil and freezes. While excessive frost buildup can indicate a problem with the system, some frost formation is considered normal as the unit operates. Therefore, recognizing this behavior helps in understanding heat pump operation and maintaining system efficiency.