If you are more specific on what is not working on your Tour, I will try to help you.
Black smoke is an indication of poor combustion. Can be caused by many, many things.
The first thing I usually recommend is to replace the nozzle in the diesel burner. The nozzle is inexpensive and pretty easy to replace.
Aqua-Hot reworked some of their manuals to include excellent directions on how to do it yourself nozzle and filter replacement. Let me know what is the model number of your Aqua-Hot and I can point you in the right direction.
Link to my Forum is below. Lots and lots of information about Aqua-Hots.
- Roger Berke -