Jeff,
Speaking from experience, there are many variables that could cause the
problem you are describing, very few of which can be fixed with WD40.
I would suggest you call in a HVAC expert. Then again, if you "just"
purchased the condo (new) it should sill be under warranty. Then
again... even if you purchased it used, it may still be under warranty.
It's not uncommon for heating units to have 10-year guarantees from
their original installation date. (although you will still get hit with
a service call / trip charge)

That said... if you want to read more on your problem I would suggest
you check these two links. Both will redirect you to some older
postings in this alt.home.repair newsgroup. You may need to give them a
second to complete the redirect.

http://tinyurl.com/73k32

http://tinyurl.com/bl4s3

Elton