Jaguar Repair: XJ8, car thermostat, vacuum valve

Question
I have a Jaguar XJ8, I just bought it about 3 months ago.  I live in TN and the lady I bought it from lived in south Florida (Not sure if this would make a difference in the different coolants or not).  The heating system is not working.  The AC does work; all fans are working, but the car is not producing any heat.  I am wondering if it could be the heating valve or the auxiliary water pump; however, I have no clue where either of those are located.  Do you know where i could find those & how to check them?
Any suggestions would be great.  
Thanks for the help,
Dwayne

Answer
I sometime have the same problem. There are a few things that could be causing your problem. Your car thermostat could be stuck open.
Your heating and cooling thermostat could be bad. You could also have lose, broken or bad vacuum valve or line.

Please buy a manual. It will show you where the components are located.