It is just a matter of time.
Some people require a few days to have a feeling of Symbiosis with their Buddhas and some
take a month.
You said you did get good vapor a few times..
BUT you also said that you wasted a great deal of herb... and if not getting vapor then
the meds should still be green.
There are contradictions.
Troubleshoot first-
be sure the elements "glow" is the same all the time......
make sure dial is on tightly.
you can not judge by "numbers of hits"
I sometimes get 15 on a wand, and sometimes I get 3
If herb is smelling like popcorn then the weed is done.
if you did not get what you feel to be enough "hits" from a wand, and yet it smells like popcorn,
it may be MJ with low THC levels.
Quality of meds is the usual culprit in cases of few hits given from a bowlful.
You did not ever say exactly how long you have had the Buddha, but it does not sound all that long.
If you have been working with the DBV multiple times daily.. for over 2 weeks,
that is when these questions need be addresses. If it indeed has been that long, then you will need
a face to face visit with a proficient Vaporist to help you with any nudges here and there.
There is a learning curve.
If it is not the case that you have used the DBV daily for a couple of weeks, then you are the key.
You must find the rythm... and try a variety of medical grade Marijuana strains.
Average street MJ does not always produce thick vapor, and will only vape for a hit or two.
So... exactly how long have you been trying for success with the DBV?
How is the quality of meds?
Edit: weed caught near the element won't generally cause issues.
a "leak" or crack in the Heater cover might, however.