2014 Forester 3011ds air conditioner/heat pump vibration

[imavol]

Just curious if anyone is having the same problem we are with the Dometic 15,000 air conditioner/heat pump. When the AC is running the bunk over the cab vibrates and it can also be felt on the couch. It is also very noisy especially from the table back to the bedroom. The vibration is very bad when the fan is on high, but not as bad when the heat pump is on. We have taken the coach to the dealer several times. They have done the diagnostic tests as instructed by Dometic, and Dometic says it is within standards.

We are very, very, frustrated since this is a brand new 2014. Anyone have any ideas or suggestions? Thanks!

[phelpo]

yep, you probably have a mud dubber
nest in the bird cage. Take the cover
off and spin it.....clean it out and you'll
be all set.

Phelpo

[bgilly]

Originally Posted by phelpo

yep, you probably have a mud dubber
nest in the bird cage. Take the cover
off and spin it.....clean it out and you'll
be all set.

Phelpo

LOL, I see I'm not the only one that have these pesky buggers building nest in the most inconvenient locations.

To the OP, also check motor mount and both the fans for out-of-round. These are molded plastic and can distort and cause the vibrations symptoms you describe.

[imavol]

Thanks for the replies. Everything has been checked and there are no nests and nothing is out of balance.. One theory is the vibration is caused by where the AC is mounted, which could be a structural issue. The dealer is contacting Forest River next.

[BigJohnD]

On our Forester 3121, the AC vibrated like that and could be fealt just as you mentioned, but it wasn't a DD nest. It was either an out of balance fan, or the fan motor itself had a warped shaft. It was to be replaced, but we sold the motorhome before fixing it. Same exact problem you mentioned. Take the cover off and watch the motor / fan while it's running. Ours had a LOT of movement / vibration.

[rad_jr]

Having a similar issue on my 3100ss but here's what I found yesterday...if I remove the cover from the ceiling inside to look at the fan the vibration goes away. Put the cover back up or even put my hand toward where the air is coming out (I.e. restrict the output) and the vibration returns...almost like resonance in the ductwork?

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