AquaHot Heat Exchanger Making Whining Noise
This was an easy one.
It's located below the drawers in the bedroom and started acting up toward the end of a 2500 mile 3-weeker.
I was hopeful a drop of oil applied in the right place would do the trick. Alternatively, I hoped I had one of the PC fan style blowers and not the expensive squirrel cage, so the replacement would be cheaper.
It was cheaper and easier than that.
This view from the return air duct above the heat exchanger is diagnostic of the cause of the blower's distress. A very large bra had been overstuffed into one of the drawers and fallen down where it was contacting the fan blades. Removing the bra removed the noise. If you ever owned a 1997 U320 and are missing this piece of clothing, please let me know. It won't fit my wife or the previous owner. It's from back a while and somehow drifted into the wrong place.
Topic: AquaHot Heat Exchanger Making Whining Noise