The answer to 'why is my ductwork not heating' is that there could be several common causes, such as a problem with the furnace, blocked or damaged ductwork, or issues with the thermostat. Symptoms may include uneven heating, cold spots in your home, or the furnace not turning on at all.
Some potential solutions include checking the furnace's air filter and cleaning or replacing it if it's dirty, inspecting the ductwork for any blockages or damage, and ensuring the thermostat is set correctly and functioning properly. If you're not comfortable troubleshooting the issue yourself, it's best to call a professional HVAC technician to diagnose and repair the problem.