Furnace making strange noises.

[Campingwithourgemini]

My Dometic furnace in my Gemini is making low inconsistent rumbling noises when burning. I finally convinced the dealership service dept. there is an issue, but they haven’t come up with a solution yet. Has anyone else had this noise?

[Raeburn2000]

I’m not an expert, but have them remove the actual burner tip and clean off the inside and outside of it. They tend to rust over time. We had something similar and that helped although it didn’t entirely go away.

[Campingwithourgemini]

Ok thanks, they had the furnace on the bench testing it, said everything was normal, but when we parked a new identical Gemini beside mine we heard no growling on the new one like what mine was doing. It’s not loud but annoying in the wee hours of the morning when all is quiet.

[OldWEB]

On our propane fired water heater, with shifting breezes it will have the flame "make noise". All normal in my book.

[Campingwithourgemini]

Ok, but this furnace does it sitting in my shop. The service people said the flame is a nice blue, and the pressures are where they should be. Kind of puzzling and annoying. Just checking to see if anyone else has this problem with either the dometic or suburban furnaces.

[OldWEB]

So did the Service people hear this "noise" while it was installed in the Gemini before they removed it... odd that they would 'bench test' it, that can be done installed.
Most comment their furnaces are loud whenever they run, that is why they opt for supplemental electric heaters...

[Campingwithourgemini]

The service dept said it sounded normal to them in the motorhome, but I persisted and they took it out for a bench test. Since the new Gemini they brought over to compare never made the noise mine made, I had some ground to stand on. Have been conversing with the service manager, he has been talking to a person in Calgary ab who has given him a couple things to try, but it is a matter of trying several things to pinpoint problem and the extended warranty dept isn’t willing to spend a bunch of time and expense going on a wild goose chase. So my service manager is willing to put his own time in on a weekend to hunt for faults. It’s a puzzle.

[Campingwithourgemini]

I can live with a constant noise of a furnace, but this is a surging sound and is very hard to sleep through.

[OldWEB]

Originally Posted by Campingwithourgemini

I can live with a constant noise of a furnace, but this is a surging sound and is very hard to sleep through.

It was "rumbling" before, now you say surging.... That could be caused by changes in the battery voltage to the fan motor. Do you have a voltmeter installed on its supply, usually the house batteries, that you can monitor at those times? Or can you see the current being drawn by the unit?

[Campingwithourgemini]

Well, now, if we put both sound effects together, then that’s what I have. I may have described it before as an old wood stove with too much wood and not enough air. But on a much milder level. As the service writer at the dealership told me , it sounded like a low bass beating away in the distant. Can’t see the voltage being an issue when it acts the same when plugged into shore power, and the meter shows a constant 13+volts.

[OldWEB]

Well, it is one of those things that "you had to be there" to answer... but I will answer your original question and I know it will be right.

Has anyone else had this noise? - "Dunno..."
Good Luck.

[Campingwithourgemini]

Haha good one and thanks.

[Junodtim]

Originally Posted by Campingwithourgemini

My Dometic furnace in my Gemini is making low inconsistent rumbling noises when burning. I finally convinced the dealership service dept. there is an issue, but they haven’t come up with a solution yet. Has anyone else had this noise?

I ran my furnace for the first time this year waking up to 40 degrees outside. It was 55 inside because of space heaters. I set the furnace for 63 degrees, the rumble is good for me, that is the flame. It rumbles for about 5 - 15 seconds, it did that rumble on and off with blower running consistently for 2 minutes before the the thermostat read 63 degrees and the blower shut off after the furnace cooled off. All normal for me, but I can't sleep with it so we use space heaters.

[MLP]

Originally Posted by Junodtim

I ran my furnace for the first time this year waking up to 40 degrees outside. It was 55 inside because of space heaters. I set the furnace for 63 degrees, the rumble is good for me, that is the flame. It rumbles for about 5 - 15 seconds, it did that rumble on and off with blower running consistently for 2 minutes before the the thermostat read 63 degrees and the blower shut off after the furnace cooled off. All normal for me, but I can't sleep with it so we use space heaters.

63 degrees? You wife/boss is not on Coumadin. If she was like mine, 78 degrees could feel cold to her! I would preference 63 degrees. I am always warm.

[The Gritz Carlton]

Check that all the duct work is tight and not crimped somewhere. It could be a lose section flopping around while it's running.

[Freddie J]

That's right. I also had a similar issue in past.

[Traina]

Sounds like something loose in the housing