Strange sound on furnace start up
Over the last two years I have begun hearing buzzing sounds when the furnace kicked on. Initially it was once a month, then more and more frequent until it was every time. In the last two weeks it has started becoming more of a squeeking sound, almost like air in a line type sound. Is this dangerous or harmful to the HVAC system -- could something be wrong that is doing more damage -- or is this just annoying -- the sound doesn't really bother me and I don't want to have someone come out for just a silly sound... thoughts?