this all should be in the archives,  but you have a Eberspacher BA6 gas
heater.  the little green knob on the dash, that says "temp" is the
on/off/timer control. often times gas heaters are not used for long periods of
time, and fall into disrepair. it is basically a gasoline fired furnace that
needs periodic maintenance (plugs, cleaning, etc)
if you are not familiar w/ the unit, have it serviced by someone who
specializes in gas heaters..  (Ark Mervis in Hoptacong (sp?) NJ makes his
living in gas heater sales and maintenance..
chris