I just installed a UV filter for the furnace after reading all the good
things here and elsewhere.

I taped up the cold air return and Spaceguard filter with foil tape before
installing the UV filter. I saw a couple of leaks I missed when I first
fired it up. So I unplugged the filter and taped up the spots I missed. But
there are still a couple of indirect leaks (glow) around the humidifier and
the hatch for the Spaceguard filter. I plan to tape around the humidifier,
but I really can't tape up the door for the Spaceguard filter. Since the
furnace is in an enclosed space which keeps out man and beast, how worried
should I be about these minor leaks. Do I need to use a regular bulb (non
UV) to ferret out any small leaks?

Also I plan to write a few warnings here and there so the HVAC guy doesn't
blind himself come the annual cleaning. But I gather this is not a huge deal
or they would provide a few labels with this thing?