I have electric forced heat (I think that's what it's called) in my
house and there seems to be something wrong with it. Sometimes instead
of blowing out warm or hot air it blows out ice cold air and the temp.
in the house drops several degrees. Sometimes this is fixed by turning
it off for 20 minutes. Also, sometimes when the fan comes on something
smells like it got burnt. I was told that it's from the contacts or
something like that and while it should be repaired, it won't hurt
anything not to. Does anyone have any ideas as to why these things are
happening? The whole system needs to be replaced (it's 16 years old)
according to the repair guy.

The other problem is something my father did. I don't know what he did
but he was tinkering with the heater/fan/vents and now the one vent is
making this horrible, loud, whirring noise. It's so loud it gives me
an earache. We had this problem a few years ago and it was from a vent
in the basement being shut. I checked the basement and it doesn't look
like anyone touched them. Though I did notice that now when we shut
the basement door that there is a suction there that wasn't there
before. I'm thinking that it's from a vent but I can't figure it out.
My father claims he didn't do anything, but as usual, he's lying. Does
anyone know how I can fix this whirring problem?