You need a new fan motor.  One of the wear items.  also, the later models have
a brushless fan.  I bought one.  $75 i believe.  Draws .4 amps and is quiet as
a whisper and really draws the air, quite a large motor, 4" long x 1.5".  Plat
Cat is much quieter than the propex, and uses 1/3 the electrical power.
steve

David Wrote:
The only complaint that I have with the
heater is that the fan is noisy - doesn't it keep people up at night?  Is
there different fans that one can install that will make it quiter?  Is the
function of the fan to push the bad stuff out?  If so, would it be possible
to install the fan at the end of the pipe and suck the bad stuff out.  It's
not THAT loud, but I cannot sleep with a wind up alarm clock due to the
tick-tick-tick noise, the fan to me is just as bad.  I'm fussy I know...
but there is always room for improvements in my mind!