Heater Duct 'popping'

JoPa

Member
When using the furnace the duct work has a popping sound. It sounds like the sheet metal is expanding and contracting. When I took it back to my dealer for some work I told them about this. The tech called the factory and was told that the factory is not going to authorize work to be done on the duct work. Am I going to have to listen to this. You can hear this popping outside of the unit. Surely some thing can be done. Thanks.
 

Scott

Well-known member
heat duct

The heat duct in the Heartland Bighorn is formed out of aluminum which is typical for an RV. Yes, aluminum does contract and expand with changes in temperature, and there is often a "popping" noise at a certain temperature when the aluminum is heating up and when it is cooling down.
We have both adhered the aluminum sheet to the floor joist with SIKA, as well as screwed it to the joists with metal fasteners. It is tightly afixed and there isn't a whole lot that can be done to "adjust" it.
The ducting is aluminum and will expand and contract in the right conditions. Again, it typically only occurs at a given degree point on the "way up" when the temperature is raising, and possibly again on the "way down" when the heat has been turned off and the temperature is going down.

ST
 

tinkers

Full timers
Heater Duct Popping

JoPa, if you look in this thread, we posted a reply to this problem a while back. Ours popped so loud and hard that it sounded and felt like someone had hit the trailer. My husband fixed it. And Scott's answer is certainly typical of his answer on everything.

Tinkers
Logan & Pat
 

Scott

Well-known member
Please post your fix

Just being honest... but when I read a snide comment like that one, ("typical of his answer on everything..") it just reminds me that we will never make everyone happy. Whether or not they question my honesty, integrity or plain just don't like the answer - I will continue to do my best to answer as many posts and personal phone calls and emails from our retail customers as I can.
Though I don't know all the answers, I will continue to go out to the line and see what the workers and our engineers have to say about a situation and then I pass it on to you.

Logan and Pat - I think it would be helpful to all of us if you would post the exact fix that you were able to do on your coach that prevented the aluminum from popping. If there is something different we can do at the factory - I'd like to implement it asap.
 
Scott said:
Just being honest... but when I read a snide comment like that one, ("typical of his answer on everything..") it just reminds me that we will never make everyone happy. Whether or not they question my honesty, integrity or plain just don't like the answer - I will continue to do my best to answer as many posts and personal phone calls and emails from our retail customers as I can.
Though I don't know all the answers, I will continue to go out to the line and see what the workers and our engineers have to say about a situation and then I pass it on to you.......
=============================

Scott,
Can't ask for anything more than being honest and trying your best.

Hope a suitable answer can be found.

Bill B. (Michigan)
 

tinkers

Full timers
Heater Duct Popping

We posted our fix on this a while back in another thread about this under Landmark. We cut out styrofoam strips and inserted them into the ducts, and it stopped the noise. They fell during travel after a few days, but we put them back and they have been quiet ever since. We are in central Florida, but it has been in the 40's almost every night the last 2 months and we have used the furnace every night. We had 2 other 5th wheels and never had this problem before, and no one we know has this problem with their units. Try this......it certainly worked for us.
 

tinkers

Full timers
Heater Duct Popping

Okay, JoPa, I got my husband to sit down and write out exactly what he did, so here goes: Our most noise was from the rear vent area so removed vent grill and wedged a 1x3" styrofoam piece in the duct at the forward edge of the vent. While on the road, the styrofoam compressed, so it was replaced with a 1x2" piece of wood. The vertical dimension was near 3", and the styrofoam trick was also used to keep one of our a/c ducts from collapsing again, as it had been when we bought the unit.
Hope this helps you. The noise is irritating and causes you to jump out of your chair sometimes!!! :)
 

timk

Well-known member
Scott,
For what its worth, I think your doing a very good job of representing your company and putting up with all the owner requests, *****es and questions. I wouldnt want your job for sure. Had one similar in my past life, it gave me heartburn. As you well know, in forums like this you dont get too many pats on the back, or someone telling you that someting that aint broke is working fine. Keep up the good fight.
TimK
 

BigBlue

BigBlue
Scott
Is it necessary to "glue and screw" the duct down? In a house the duct work is allowed to move quite a bit because the duct is not restricted except at the ends. Through the framework the duct is supported but not restricted. An installation like that might minimize the poppingl.
 

Scott

Well-known member
Duct

Yes, it is necessary to glue and screw the aluminum down as it utilizes two of the floor trusses to form the "duct". What we are glueing and screwing down is a rolled out layer of aluminum sheet that is seamless. Utilizing the aluminum studs (as long as they are seamless) is something that is common in a lot of RVs that do not use wooden floor trusses. To get a good seal all along the trusses, the sikaflex is applied the full length, and then screws are added to ensure it's integrity.
Just a note - we did have a rare occasion where one floor was making a strange noise, and it turned out that the flooring guys had missed the studs in a couple of areas when they were screwing down the seamless floor decking - so some of the screws went into the aluminum ducting. Then, as the aluminum constracted and expanded, it would move, or rub along those screws as it went up and down and made a loud noise. When those stray screws were removed, the noise went away.

ST
 
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