Originally Posted by pmclemore
I'm kinda with...
there is NO reason to run pressurized air into the btf...
the line goes UP and then DOWN to tank level.
so water drains OUT of the line naturally if the head isn't obstructed,
or the check valve plugged.
the line is butyl not pex and not rated to the same pressure as the normal plumbing.
it's also buried in the trailer wall behind cabinetry and not easy to access if it starts leaking.
in fact NOTHING on the black tank side is rated for 'pressure'
so if the vent is obstructed (wasps/turds/paper) ANY pressure is bad.
there are several places that leaks or blown seals could happen with pressure.
while the op probably did no harm since it is new,
the tank heads tend to PLUG up over time.
that means AIR in the line would never reach the tank or tank vent.
so pressurized air (or water) would escape at the check valve or a joint.
neither are good things.
gravity drains the btf lines.
the owners manual is reasonably specific,
about HOW and where to blow out lines with compressed air...
the btf line isn't part of that process for good reasons.