Furnace very loud

[wsthomas1]

I have a 2020 Thor 27R with a Dometic DF series furnace. When I first turn on the heater, the blowers start and run for a few seconds, then it appears the LP kicks and makes a very loud roaring noise until the coach reaches temperature. Then the roaring stops, the blowers run for a few minutes then they shut off. The noise is actually louder on the outside of the coach and disturbs my fellow campers.

Can anybody tell me the cause and any solutions to this problem. I would really appreciate it.

Thanks in advance.

[ducksface]

It's just the flame in a venturi being a flame.
Have you listened to your disturbed camping neighbors furnaces as a comparison?


Some well placed rock wool or sound guard of some sort will help you a bit with the inside noise but not the outside.

(a propane fridge makes a similar but quieter noise)
(so does a tankless water heater, about as loud as the coach heater)
(so does any modern home furnace powered by any gas)

I'm going to guess that all 62.000 btu furnaces make very close to the same outside noise as any other 62,000(insert your number here) propane heater.

[Long & Winding road]

I worked on this a couple of years ago. I insulated the cold air return and it helped some overall (on the inside) but its just as loud on the outside. I did a write up on this if you want to do a search (I will see if I can find it and post it hear later).

I also stuffed insluation under every cabenet / drawers to absorb sound (perhap keeps a little more heat in or out of the RV depending on the season?)

IMO all of these furnuces are loud so most likey yours in operating fine. It wakes me up at night so I will heat up the RV some before I go to bed then turn it down to like 60 at night so it minimizes the amount it come one. I also will use a ceramic heater if its really cold when im plugged into shore power. But I dont do much winter camping so its not an issue for me.

Try insulating the cold air return and see how you like it. Let us know how it turns out.

[Long & Winding road]

Found my old writeup. "How I insulated my heater last winter". I hope this helps.

https://www.thorforums.com/forums/f2...ter-14324.html

[ducksface]

https://www.amazon.com/dp/B01CTM0H1S...v_ov_lig_dp_it

Easy to build, easy to buy.
The noise doesn't bother us so I haven't done this yet.
When I put in the thermostatically controlled duct to the basement, I'll put these in while it's all torn apart.

(I think a 2 liter soda bottle stuffed/lined with scotchbrite would work really well.)
(so would a plastic shoe box from Walmart with some cardboard baffles duct taped inside)

[Long & Winding road]

Ok, I just looked at this link. Was that for the "cold air return" or the "forced heated air" (or both)?

Very intresting (but expesive). But you might need 2 or 3 of the 8 inch size for the Cold Air return so your not restrictive.

I like your idea of the home made baffle.

But if the noise really bothers you it might be worth it to some.

Thanks for the info.... I never seen that baffle before.

[Bob Denman]

I know that the furnace in our Outlaw would drown out the sound of me snoring...
The Missus kind of liked that.

[ducksface]

I wonder if a laminar jet would work for air?
Not the jet itself but a 2 liter bottle stuffed with drinking straws?
Would the laminar effect affect the white noise sound of the Unchecked duct?

[16ACE27]

Originally Posted by wsthomas1

I have a 2020 Thor 27R with a Dometic DF series furnace. When I first turn on the heater, the blowers start and run for a few seconds, then it appears the LP kicks and makes a very loud roaring noise until the coach reaches temperature. Then the roaring stops, the blowers run for a few minutes then they shut off. The noise is actually louder on the outside of the coach and disturbs my fellow campers.

Can anybody tell me the cause and any solutions to this problem. I would really appreciate it.

Thanks in advance.

How's your water heater sound? Should be similar to the furnace. If either is unusually loud the air/gas mix may need to be adjusted slightly. The manual tells you how to do that.

[99dart]

WHAAAAAT???? I can't hear you... the furnace is TOO LOUD!!

[wsthomas1]

Thanks everyone for the info and ideas. The sound inside isn't that bad, it's the outside exhaust that's really loud. i like the idea of building that baffle, but the exhaust is pretty hot, so it would have to withstand some heat.

Does anybody know if there is an adjustment that can be made to reduce the gas flow without affecting the function of the heater too much?

[jeffpiercemagic]

Originally Posted by wsthomas1

I have a 2020 Thor 27R with a Dometic DF series furnace. When I first turn on the heater, the blowers start and run for a few seconds, then it appears the LP kicks and makes a very loud roaring noise until the coach reaches temperature. Then the roaring stops, the blowers run for a few minutes then they shut off. The noise is actually louder on the outside of the coach and disturbs my fellow campers.

Can anybody tell me the cause and any solutions to this problem. I would really appreciate it.

Thanks in advance.

Mine sounds like a literal jet engine starting up, LOL!

Jeff

[Badmanrick]

All furnaces are LOUD. At least you know it is working properly.

[hikerjohn7]

Originally Posted by wsthomas1

I have a 2020 Thor 27R with a Dometic DF series furnace. When I first turn on the heater, the blowers start and run for a few seconds, then it appears the LP kicks and makes a very loud roaring noise until the coach reaches temperature. Then the roaring stops, the blowers run for a few minutes then they shut off. The noise is actually louder on the outside of the coach and disturbs my fellow campers.

Can anybody tell me the cause and any solutions to this problem. I would really appreciate it.

Thanks in advance.

I too have noticed that the furnace in my Jayco Precept (now a Thor product) is loud when the burner turns on. I checked it out and everything looked OK so I guess it's the nature of the beast. It operates and heats fine otherwise.

[MLP]

If you are bothered by the noise and going to keep your rig for many years, then you may want to look into cheep heat. 30 or 50 amp electrical heating elements added to your furnace. It is in addition to the propane. That way when you have a power post, you can use the electric and be quiet and save on propane. Just one answer to the noise. I am not promoting it and do not have it or want it. The noise does not bother me, but maybe a solution to some that are.

[hikerjohn7]

Originally Posted by MLP

If you are bothered by the noise and going to keep your rig for many years, then you may want to look into cheep heat. 30 or 50 amp electrical heating elements added to your furnace. It is in addition to the propane. That way when you have a power post, you can use the electric and be quiet and save on propane. Just one answer to the noise. I am not promoting it and do not have it or want it. The noise does not bother me, but maybe a solution to some that are.

Once I determined there probably was nothing wrong with the unit, the noise didn't bother me anymore. In fact, the white noise may be why I sleep so well in the RV. I have not yet had neighbors complain. Perhaps theirs does the same. But the electric heat suggestion is good for not-to-cold weather. I take a space heater when I plan to have some cold nights and it really does knock the edge off so that our comforter suffices to keep us warm.

[MLP]

Originally Posted by hikerjohn7

Once I determined there probably was nothing wrong with the unit, the noise didn't bother me anymore. In fact, the white noise may be why I sleep so well in the RV. I have not yet had neighbors complain. Perhaps theirs does the same. But the electric heat suggestion is good for not-to-cold weather. I take a space heater when I plan to have some cold nights and it really does knock the edge off so that our comforter suffices to keep us warm.

Be careful with the space heater. Another couple died in Florida at night do to a fire caused by a space heater. Several a year happen, but we too use one.

[hikerjohn7]

Originally Posted by MLP

Be careful with the space heater. Another couple died in Florida at night do to a fire caused by a space heater. Several a year happen, but we too use one.

Yes, I know there is a risk so I have made sure I picked a circuit that is not overloaded. I chose a high quality, safely designed heater and I do not run it on a high setting.

[Walter Brauer]

Originally Posted by wsthomas1

I have a 2020 Thor 27R with a Dometic DF series furnace. When I first turn on the heater, the blowers start and run for a few seconds, then it appears the LP kicks and makes a very loud roaring noise until the coach reaches temperature. Then the roaring stops, the blowers run for a few minutes then they shut off. The noise is actually louder on the outside of the coach and disturbs my fellow campers.

Can anybody tell me the cause and any solutions to this problem. I would really appreciate it.

Thanks in advance.

I removed the furnace access panel inside the coach and discovered when the burner is on the outer sheet metal furnace housing is vibrating loudly, causing the noise. Putting my hand on the vibrating furnace panel quiets it down to "normal" noise level. I'm researching a suitable dampening material to stick on the sheet metal but it must be temperature and flammability suitable.

Or, looking for other simple solutions.

[macdaddy1111]

2020 hurricane here

Ours sounds like I am back on carrier deck with jet taking off. Haha

Was camping neighbors that brought it out attention

Only has one exhaust port.

will make video when it gets into the 30s here in Tampa! ha