Atwood Hydroflame 7900 II Screeching - Motor replacement?

Discussion in 'Miscellaneous Repairs & Maintenance' started by ca8781, Jun 19, 2019.

  1. ca8781

    ca8781 New Member

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    Hi All, I have a 1995 fleetwood avalon that is making a terrible noise when the furnace fan kicks on. I've attached a short video of the sound here:

    The noise continues for about 60 seconds then the furnace kicks on and its fine for the night. The issue only occurs during initial start up. Outside temperature is a factor also. When I test the furnace at home when outside temp is 65 + degrees the squealing from the furnace does not occur. When were camping in 35 degree weather the screeching occurs. I've tried both A/C power and battery. I'm thinking the motor may need to be replaced. Anyone agree or have other thoughts? Has anyone here had any luck replacing the motor on a 7900 II furnace? Did you have to remove the furnace from the trailer?
     
  2. Anthony Hitchings

    Anthony Hitchings Well-Known Member Silver Supporting Member

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    Both my bathroom fans screeched at our house. A few shots of WD40 has lasted over 5 years so far (no screeching of any kind). So you might try that. WD40 is not advertised as a lubricant, but for some applications it seems to work quite well.
     
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  3. JT2

    JT2 Member

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    Nope, not the motor ... it's the fan pivots/ bearings/ axle -- whatever. After a few years they dry out -- the heater in my former camper did that for years. Usually the noise would stop after the fan and unit warmed up and yes, it is temperature sensitive. I tried several times to get at or into the fan housing but found it would require more disassembly than I was prepared for. We didn't use the heater enough to make it a big problem.
     
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  4. MNTCamper

    MNTCamper Well-Known Member

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    If you can access the fan bearing mounts to lube them, that would be best. I have the same thing on my woodstove fan. Motor is actually fine, but the other rotational points need periodic lubing.
     
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  5. Sjm9911

    Sjm9911 Well-Known Member Gold Supporting Member

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    Try to oil it first. Use motor oil if you can.
     
  6. tenttrailer

    tenttrailer Art & Joyce - Columbus, O

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    I would use electric motor oil. If you can not find any 3-in-1 will ork.
     
  7. Sjm9911

    Sjm9911 Well-Known Member Gold Supporting Member

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    3 and 1 gets gunky to fast. Dont ever use it. Nothing will beat out plane old motor oil. It evaporates less, so dosent seize up. I use it on everything now that i know that. I used to do a lot with model trains, one guy there was a oil expert( he atually made it and tested it) , lol. And with all the stuff that sat around and didnt get constent use the motor oil did the best. I then remember as a kid oiling the door hinges on the house. Then later in life noticing how sticky they get. All 3 and 1 oil. Motor oil will atually help dislove the older gunked up stuff and make it unsticky. Never used electric motor oil, and no one i know on the train fourms ever did either? Might be good.
     
  8. Snow

    Snow Well-Known Member

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    Could be the bird cage fan on the moter too.. seen them fail in a number of vehicles.
     

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