Originally Posted by colemole
The dealer told me its the expansion /contraction of the plenum which is under the bed and there is nothing can be done. True?
The SALESMAN told you.
Dealers LOSE money doing repairs.
The squirrel cage fan is mounted in a rather tight fit housing but it is on bearings and should NOT be making sheet metal banging and clicking noises.
It's probably a very minor thing to remedy.. like something is loose or something has found it's way into one of the openings. Someone will need to open up the cover (6-8 screws on the side wall) and look into it.
If it (the source of the noise) is deeper into the unit... then the duct hoses and the LP pipe will need to be disconnected so the housing can slide out through that side wall opening.