Heat not working?

Loss of heater output described as heat rather than airflow indicates low coolant level. Inoperative temp / blend door. Loss of airflow means the blower is not correctly operating. Control functions that are changed by the operator, that result in a soft thud are possibly the normal operation of the doors which direct airflow and add heat or block it. The kind of system used in your model must be known. Manual, automatic or semi. Trey to find what you have, note things about it, read about it. correct your coolant level. test your systems operation and try to use the terminology they use in the manual provided in the glovebox. Keep describing the issue till you get an answer you can relate to, or show it to your dealer for clarification. They can help with info. They can help with parts, and technical issues that are known to cause your concerns.

Try not trey. And a noisy blower when changing the speed may have to have it's motor replaced or obstructions removed.