The answer to 'difference between furnace repair and' is that furnace repair involves fixing specific issues with an existing furnace, while furnace replacement involves completely replacing the old furnace with a new one. Furnace repair is typically less expensive and can extend the life of your current furnace, but may not address underlying problems. Furnace replacement is a more comprehensive solution, but has a higher upfront cost.
Furnace repair is often the best option if your furnace is relatively new or the issues are minor, such as a faulty thermostat or broken blower motor. Furnace replacement is recommended if your furnace is old, inefficient, or has recurring issues that are costly to fix. Replacing an old furnace can also improve your home's energy efficiency and indoor air quality.