Humming furnace

[Pinkfloydfan123]

Hello. I'm new to the forum and am new to Forest River. My wife and I just bought a new Palomino Solaire 197x and we really like it so far.

On our first outing I turned the furnace on and it put out good heat. But periodically it starts a high pitch humming that lasts about a minute and then goes away. Then it will come back a few minutes later, last for a minute and go away.

I'm a newbie so I'm not sure where to look. Worse case it is under warranty and I can take it back in.

Thanks.

[Dave_Monica]

Welcome to the forum. Does the sound you're hearing seem to be with the furnace blower fan?

Dave

[Herk7769]

Pardon me but; can you just teach it the words?

OK, joke aside, is the sound in the duct work or the actual furnace?

A torn duct can vibrate under the right flow conditions (starting up or shutting down).

The fan can have debris or a bugs nest on or in it (squirrel cage type fans).

[fonzie]

Does the noise happen when you are hook up to shore power or on battery supply. I'm asking because it could be actually your converter fan that comes on every so often when furnace is running and your are on shore power. When you hear noise again and you are on shore power, remove shore power and run on battery for a while and see if noise goes away.

[Pinkfloydfan123]

Many thanks for the replies ... sorry for the delay in getting back. Here is what I can tell you.

1) It doesn't matter if I'm on shore power or battery. For grins I did get close to the converter fan and it isn't the converter (it's actually pretty quiet).

2) I took the furnace cover off the front of the furnace (inside under the wardrobe) and I heard the hum ... but not as loud as outside.

3) I took a flashlight and looked into the opening from the outside and didn't see anything in the vent ... which only means there is nothing that I could see.

A couple of other notes.

1) The second (third and fourth) day I used the furnace I heard the hum ... just not as frequently.

2) When I'm outside and the hum starts I can put my hand up to the vent (close to the vent ... not actually stopping the airflow) and the hum goes away. When I move my hand it comes back.

It's weird. Like I said ... it is under warranty so I think I'm going to take it in and let them work it out. I was just hoping there was a "easy fix" without going an hour to the dealership.

Thanks again!

[Herk7769]

The furnace burner fan might be rubbing something.
It could be a bug nest (hornet or such).

The motor is in the center of two squirrel cages fans, one provides combustion air and one that actually circulates the hot air in the camper.

[Pinkfloydfan123]

Ahhh.... Ok, that makes sense. I'll take a look at this in the next couple of days.

Thanks for taking the time to post the pic.