Excessive fan noise

[iezzif]

The passenger side floor vent behind the seat on my 2003 Itasca Sunflyer emits a noticeable whine. There appears to be little access to the area in question because it sits atop/behind the water heater. Anybody else have that issue?

[Morich]

Some questions take some time to get the attention needed to get answers from the right people. Looks like you are hitting a dry spell on yours, so perhaps I can ask some questions to get the conversation started!
First let me check to be sure we are speaking the same. You are speaking of noise from the duct for the furnace ?
I might expect the furnace to have a blower and all ducts fed from that single blower. So that would normally make noise at all the ducts and coming from the furnace itself, rather than anything at that one duct. Possible that you are setting in a location where you hear noise from that one duct, when it might also be coming from several, just more noticed there?
Just theory but I might first want to go to the furnace and see if the blower is making the whine.
But there may also be others with far more experience with that RV and they may have far better info as I've never used that coach. Good luck and maybe some help will be along shortly?

[Chuckmor]

Sounds like you have a 'coach heater' which in fact is behind the water heater. Do you have a rocker switch on the dash with hi/low settings? If so, do you hear the whine with the switch in the off position?

This heat exchanger has hot water from the engine (while driving) and a blower motor and fan to blow heated air into the floor vents. When the rear propane heater is operating, it also blows heated air into the floor vents. A couple of flappers allow whichever blower is operating to supply air to the vents. Here is a link to a detailed description of how someone overhauled the blower in his Itasca. I'm in the process of getting to the heater in my Adventurer. It's a major project.

http://www.rvforum.net/miscfiles/WH_...H_Repair-1.pdf

And a link to older forum threads.

http://www.winnieowners.com/forums/f...er-218288.html

I never knew what the Coach Heater switch was for - it never did anything. If I didn't need to get to the back of the water heater, I wouldn't mess with it since we've gotten along without it all this time. But now I'm into it, and may yet abandon the project.

Good luck if you tackle it.