I have an 84 Vanagon with no heat... actually sometimes it heats up,
sometimes not (most of the time NOT now)....I had it in the repair shop the
other day to have some exhaust work done. They indicated to me it was
probably the heater core.  I am assuming that since it works intermittently,
perhaps the core is clogged up.  What is the best way to flush this out? Or
is flushing this out the way to go perhaps if it in fact is the heater core
that is clogged.  It's 27 here today....good thing it isn't my daily driver!
Any suggestions are appreciated.....

Harold Jaynes
Washington DC