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UFC: mouse vs condenser fan blades ...

Hi everyone. Neighbor's heat pump compressor was making a horrible metal-on-metal type rattle noise. When it stopped, I found a very dead mouse in the bottom. Poor guy got banged around. a lot. Lost in the first round, for sure.

Should they be concerned about the fan blades being out of balance? Is balance a thing on these units like it is on, say, mowers? Should they have a tech visit?

DIY'er ... ripped out a perfectly good forced-air furnace and replaced it with hot water & radiators.


  • Jamie Hall
    Jamie Hall Member Posts: 22,196
    Run the fan. If you hear any metal to metal noise or it vibrates, the mouse put up a brave fight and bent one or more of the blades -- and they will need to be straightened. That should also get rid of minor vibration; major vibration may indicate really badly bent blades which may need replacement.
    Br. Jamie, osb
    Building superintendent/caretaker, 7200 sq. ft. historic house museum with dependencies in New England
  • Boon
    Boon Member Posts: 260
    Thanks Jamie. I went back to their house [they're out of towners] and it was running quiet again; I didn't get close enough to hear/notice any vibration but I'll do that in a day or two after the crime scene is a little less infectious.

    I was concerned the mouse was going to get picked-up again and again on every cycle but apparently not. I imagine these one-off fights between mice & fan blades are more common than anyone might guess.

    Thanks again.
    DIY'er ... ripped out a perfectly good forced-air furnace and replaced it with hot water & radiators.
  • Dennis
    Dennis Member Posts: 101
    I can't imagine a mouse could knock a fan blade out of balance in fact I'd say that is impossible. However the mouse might have been useful in directing you to the condenser where ice put the blade out of balance. The quieting might be from the ice dropping off. One other issue might be a loose hub on the blade. If the blade starts making a racket again, put a few drops of oil between the hub and blade connection if the noise stops the hub is loose. Time for a new blade, or in a pinch if you carefully hammer the mushroom holding the hub to the blade you might save the blade.
    Just do it, right.
  • Larry Weingarten
    Larry Weingarten Member Posts: 3,143
    Hi, I'd be looking for ways to keep that mouse's relatives from getting in there and trying to get revenge!

    Yours, Larry