Ohio winters are hard on heat pumps because they spend much of the season near the balance point, switching between compressor heat and auxiliary strips. A unit that blows cool air in heating mode, ices over on the outdoor coil and never clears it, short cycles, or runs constantly while the electric bill climbs usually has a specific fault rather than general wear. Common causes are a stuck reversing valve, a failed defrost board or sensor, low refrigerant charge, a weak capacitor, or auxiliary heat that has locked on.
Some frost on the outdoor coil in cold weather is normal; a solid sheet of ice that survives a defrost cycle is not. A professional will test defrost operation, measure refrigerant pressures and superheat, and check the reversing valve and airflow. Pro HVAC connects homeowners in Worthington, OH with HVAC professionals. Call (321) 463-9811.