New Lopi Liberty - Oil-canning - bang!

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GreenLiving57

Member
Aug 3, 2018
84
Southwestern USA
Hi,

I just installed a new Lopi Liberty (NexGen-Fyre). This was by far the most expensive stove I have ever bought. I could have bought a whole truckload of Home Depot stoves for what I paid for this stove. So far, I love the way it heats but............

I am used to the normal clicks and pops while a stove heats and cools, but this stove, at about 300 degrees, does one extremely loud BANG! It then does it again while cooling down.

This likely is some sort of sort of "oil-canning". (the effect of metal contracting/expanding under heat) Very possibly on one of the heat shields, as it's a ringing sound that sounds like it's on the exterior of the stove, not a thud coming from inside.....

I have spent quite some time reading many threads here on this subject.

I contacted Lopi, who while saying I have to deal with my dealer, they did say this is NOT normal, give me a few things to try - I slid a few pieces of some ceramic baffle I had, cut into cracker size chunks into each heat shield from the bottom, up a few inches, to try and tighten it up - made no difference.

I also removed screws from my stove pipe telescoping piece where it connects to the stove, and a couple feet above - just to make sure it wasn't catching and causing the issue - made no difference.

So here are my questions,
1) Maybe I need to get those baffle wedges higher, into the center of the heat shield?

2) Do you think this issue might eventually go away on it's own, as the metal gets "used" to being heated and cooled? I have only had a few fires so far and never had the stove "really" cranked up, I have been to 550 - but wondering if I give her a real work out, and take it up to 700, of this possibly might "break in" the metal to where this issue stops........?? Yeah, I'm grasping at straws here........

3) Many suggest hammering and bending the heat shields in a bit at the center - Lopi says don't do this, as it would void the warranty, and I don't exactly like the idea of hammering on a stove I just bought, and paid a pretty penny for.

4) I do know, the stove, got knocked around some, during packing, shipping, and delivery down my steep rough drive-way - Paint knocked of in spots, and various scruffing, scratches, nothing serious, or anything I would have ever been concerned about till this issue arose.

If anyone, has any tips, tricks and suggestions I would sure appreciate it. I live 2 hours from town and my Dealer, so want to try any and everything before bringing a tech up here.

Thank you in advance for any replies.

Lopi.JPG
 
Check firebox welds to see if one has popped. Watch the secondary manifold that the tubes are set into for any cracks, and to the rear supply tube.

If this is predictable, maybe set up your phone to do a video of the event. Edit the video down to a few seconds when this happens and post it here if possible. This documentation could also be presented as evidence to the dealer and Lopi. Set the camera down low, pointed upward into the firebox so that it includes the secondary rack and air deflector.
 
Check firebox welds to see if one has popped. Watch the secondary manifold that the tubes are set into for any cracks, and to the rear supply tube.

If this is predictable, maybe set up your phone to do a video of the event. Edit the video down to a few seconds when this happens and post it here if possible. This documentation could also be presented as evidence to the dealer and Lopi. Set the camera down low, pointed upward into the firebox so that it includes the secondary rack and air deflector.
Thank you so much for these suggestions. Unfortunately, the "bang", happens somewhere in a 30 minute window, and I can only run my camera for a few minutes till the batteries die, so very hard to catch on video. I have started the stove about a dozen times now, and the bang happens every time, while heating, and cooling, without fail, I just can't catch it exactly......

I will follow all your advice in checking the interior when the stove cools down over night. Right now, with a cold front, and rainy weather, here in the Rockies, I have the stove cranked up! She sure puts out a lot of heat!
 
My osburn 3300 has crossbreak in the side panels to supposedly eliminate oil canning.it bothers me looking at the creases in the side panel and I asked sbi to sell me panels without the creases, they would not.my 2300 osburn had same panels without the crease and never had an issue.
 
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Here is an attempt to show what the sound is like. This is NOT "the" sound, but an approximation using a rubber mallet.

As the video shows, when tapping the side heat shield, it's a bit higher pitched that when tapping the back heat shield, that is closer to the sound. One possible issue, is the rear heat shield, has the round cutout, meant for a blower, or pipe, partially cut out - it moves in and out - could this be catching? Maybe get it knocked out, and wedge a ceramic baffle chunk right there more in the middle, that from the bottom which I already did which had no effect?

If the issue is much more serious, and coming from the main body of the stove - a faulty weld - I'm wondering if would still cause the heat shield to ring? ........questions, questions, no answers yet. About the only thing I have ruled out is it is NOT coming from the stove pipe, as I took the screws out, and have stood right next to the bloody stove all day, heating it up, and down, to wait for the sound to shock the livin' heck outa me....... ;)
 

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  • Lopisoundtest1.mp4
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I could understand the rear shield deforming considerably considering the very tight install. What exactly is that wall made of? Don't believe I've seen an install that close. Ever!
 
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I could understand the rear shield deforming considerably considering the very tight install. What exactly is that wall made of? Don't believe I've seen an install that close. Ever!
It's actually a few inches away, the pics are deceiving - from my non combustible stone hearth - and above that a rammed earthen wall. Not touching at all. But yeah, it's closer than in most "normal homes" made from conventional materials.
 
I have the Endeavor Nexgen and it does the same thing. Not as predictable as yours but it does pop and bang every time its used. Travis Industries has a great warranty on their stoves so if theres an issue they will take care of it.
 
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Thanks for the reply. This stove has all normal clicks, and clanging that I expect from steel wood stoves, And with over 50 years of experience with stoves, I have had many different types and styles - but this loud "bang", is a new one for me, and drives me crazy, at night, it wakes me up like a gunshot EVERY time it heats, and cools above 300 degree range!!! I had an older style Endeavor for over 25 years, and never heard this type of sound from it.

I absolutely LOVED my old Endeavor, and this new Liberty heats extremely well so far. But this bang...........
 
The rear shield could be the issue or it could just be resonating from an internal bang.
Strictly for diagnostics, can the rear heat shield be temporarily removed for a test fire? That would isolate the issue to the rear shield or eliminate it as the culprit.

Also, is the stove level, and are all legs even, on the same plane? If not, the body may be getting torqued slightly.
 
The rear shield could be the issue or it could just be resonating from an internal bang.
Strictly for diagnostics, can the rear heat shield be temporarily removed for a test fire? That would isolate the issue to the rear shield or eliminate it as the culprit.

Also, is the stove level, and are all legs even, on the same plane? If not, the body may be getting torqued slightly.
Thank for your reply.
The stove is level. It has a couple quarters put under one leg to make it so. It appears to be sitting quite good, there absolutely no wobble - and I don't believe that is the issue. It could be a fraction of 1/32 of an inch or so off, but I don't think enough to warp it in anyway to cause this issue?

Lopi Tech support at first advised me to take off the heat shields for exactly what you advise - remove them and see if the sound still happens. However, once I started asking more detailed questions, concerning screw bit sizes, they completely changed their tune, and said I could void the warranty by doing this, and told me to "deal with the dealer" - whom I have now been waiting two days for a response.

Removing the side heat shields will be easy. The rear one however, will need to have to darn stove moved out a few inches to access the lower screws. Not an easy task for a 570 lb stove on a rough stone surface......

I did tell the dealer when I spoke with them that this is no "emergency", and that the stove is still working great, other than the "BANG"!!!

Let me make it perfectly clear at this point, I am not taking bad about Lopi or my Dealer - I'm neutral for now.

But Lopi, DID tell me this "Oil-Canning" (as they called it") is NOT normal.
 
It isn't normal and should be addressed. Start with removing the side shields and test that way as a process of elimination. Move away combustibles from the sides 36" when testing.
 
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I would take a straight edge (that can handle the heat), and look at all possible different surfaces to see if they are convex or concave. Then do it again for all after the bang. See if one changed. If so, that's the surface that pops.

First taking off as many shields as possible is a quick way to eliminate those.
 
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I would take a straight edge (that can handle the heat), and look at all possible different surfaces to see if they are convex or concave. Then do it again for all after the bang. See if one changed. If so, that's the surface that pops.

First taking off as many shields as possible is a quick way to eliminate those.
That was an absolutely great suggestion, and I just tried it.

The back heat shield was perfectly flat and level before and "after the bang".

The side heat shields DO have a "concave" surface, from side to side, I can get a quarter dropped through the gap, both sides have this, but the concave, and gap was still there "after the bang",.......so I'm back to square one.

At this point, the next step is the Dealer is sending someone up here to inspect the stove. For now, I live with great heat, and "BANG"!

Once on the "way up", and once on the "way down".

I have noticed that the "bang" can be anywhere from 275 - 400 degrees. And ONLY once each way, never more.
 
If anyone has any clue what the exact size and type of screw this is, that Lopi uses to attach the Heat Shields please let me know. I have tried all bits of various sizes in my tool box , and haven't got it yet, and don't want to damage, strip it. I need the exact bit.

Lopiscrew.JPG
 
Looks a bit like what I have for decking screws. Is it toothed on the inside?
 
That was an absolutely great suggestion, and I just tried it.

The back heat shield was perfectly flat and level before and "after the bang".

The side heat shields DO have a "concave" surface, from side to side, I can get a quarter dropped through the gap, both sides have this, but the concave, and gap was still there "after the bang",.......so I'm back to square one.

At this point, the next step is the Dealer is sending someone up here to inspect the stove. For now, I live with great heat, and "BANG"!

Once on the "way up", and once on the "way down".

I have noticed that the "bang" can be anywhere from 275 - 400 degrees. And ONLY once each way, never more.

Too bad it didn't give useful results.

If you take the shields off as was suggested earlier, can you do the same on the inner walls?
 
If one screw hole is off in any way of that sheet metal shield it can bind it and possibly cause it to pop as it expands and contracts. I’m talking about a screw hole in the sheet metal that may be slightly misaligned with the hole in the main body it’s attached to. That could be one cause, but I doubt if that is it. Perhaps it could be a few screw holes that are not aligned properly. Only takes a few thousandths of an inch to be off and bind things, but I doubt it is that, but it could be.

Couple the binding above with tightened fasteners not allowing it to move, that could be it, but I doubt it.

One fix for such cases above, would be expanding each screw hole in the shield horizontally to form slots and then not tightening the fasteners so tight. You could even use blue lock tight on the fasteners and then only tighten them enough that there’s a few thousandths gap between the shield and the fastener heads allowing for expansion and contraction. I am talking about slots similar to slots in vinyl siding and leaving the nail heads loose, not hammering the nails all the way down so the siding can move on the house with the weather.

Somehow, I don’t think that is the issue or the fix though.

My first question I would ask you is how fast are you getting that stove to 500?

You mentioned 30 minutes, but it wasn’t real clear to me in your post if you got the stove heating that hard that fast or not.

Most manuals today say to build a quick hot fire (to satisfy the EPA for less smoke at start up).

Try something for me…
You might first try something that doesn’t involve any tools or cutting 1/8”-1/4” long slots in a shield and that is to simply gradually warm the stove from cold to 500 over an hour or even two hours and see what happens. It’s worth a shot to try. The technique (slow heating) above could be coupled with the above suggestions (loosening of screws/slots) to arrive at a solution.

That may not be the issue either, but that is my first inclination, to ask how fast are you heating the stove.
 
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If one screw hole is off in any way of that sheet metal shield it can bind it and possibly cause it to pop as it expands and contracts. I’m talking about a screw hole in the sheet metal that may be slightly misaligned with the hole in the main body it’s attached to. That could be one cause, but I doubt if that is it. Perhaps it could be a few screw holes that are not aligned properly. Only takes a few thousandths of an inch to be off and bind things, but I doubt it is that, but it could be.

Couple the binding above with tightened fasteners not allowing it to move, that could be it, but I doubt it.

One fix for such cases above, would be expanding each screw hole in the shield horizontally to form slots and then not tightening the fasteners so tight. You could even use blue lock tight on the fasteners and then only tighten them enough that there’s a few thousandths gap between the shield and the fastener heads allowing for expansion and contraction. I am talking about slots similar to slots in vinyl siding and leaving the nail heads loose, not hammering the nails all the way down so the siding can move on the house with the weather.

Somehow, I don’t think that is the issue or the fix though.

My first question I would ask you is how fast are you getting that stove to 500?

You mentioned 30 minutes, but it wasn’t real clear to me in your post if you got the stove heating that hard that fast or not.

Most manuals today say to build a quick hot fire (to satisfy the EPA for less smoke at start up).

Try something for me…
You might first try something that doesn’t involve any tools or cutting 1/8”-1/4” long slots in a shield and that is to simply gradually warm the stove from cold to 500 over an hour or even two hours and see what happens. It’s worth a shot to try. The technique (slow heating) above could be coupled with the above suggestions (loosening of screws/slots) to arrive at a solution.

That may not be the issue either, but that is my first inclination, to ask how fast are you heating the stove.
Thank you for all the responses. I so appreciate any and all thoughts! Allow me to respond to each.

First off, there has been a "slight" change. It banged twice yesterday, once at 275 - lower than ever, and once at 425 - higher than ever. It also DID NOT bang on the way down! woo hoo, 50% fixed!?!

I just found something online (look long enough you can find anything online of course), and it gives me a glimmer of hope -

"With time, the metal will usually "relax" into its range of expansion and contraction, and the oil-canning will stop on its own"​


In regards to if the screws are toothed inside, no, it's some sort of maybe allen type that I don't have? This is such a simple thing, Lopi must have boxes of jillions of them......yet Lopi tech support told me all screws are the same, the typical slot type which one side of the heat shield DOES have, it's these little bugger's on the other side that I haven't found a bit that fits yet. I can only assume whomever was handling the tech support this week was confused about what stove I actually have - a brand new, Lopi Liberty NexGen-Fyre. Unfortunately, Lopi cut me off, and said I must deal direct with my Dealer.

Regarding the detailed info on screw hole sizes. It sure doesn't sound like just a screw hole popping, it's so loud, but at this point, it could be anything?

Regarding how fast am I getting the stove heated up - it varies a little each time, depending on how good my kindling is, and how much I tend it the first few minutes. I do know I have had it up to 500 both quickly, and slowly, and the bang happens every single time, including the "two bangs" I just described yesterday. Last night I tried to get the stove hotter than ever before, up to 600 (and yes, I cooked myself outa here in this cool fall weather).

Thanks again for any and all replies!
 
Be sure the technician that comes out brings along a toolkit with the appropriate screwdriver tips. The fix may be as simple as loosening the screws. I was thinking the same thing as Hoytman. If removing the shields fixed the issue then I would slightly enlarge the holes in the shield. If the stove has a blower on it, then I don't think leaving them a little loose is a good idea. The panels tend to resonate at some frequencies and can make an annoying racket when the blower speed is just right.
 
Those screws look more like painted-over rivets to me.

To see if the shield is moving under them you can draw a line or X across the "screw" and shield with magic marker when cold and then see if the lines still line up when it's hot. Probably need to do all of them that you can get to in case it's only one that is moving. Magic marker comes off with a quick wipe of solvent but test first.
 
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I have built my own entire house, have jillions of different types of screw-heads, including several different torx sizes, and none match up - so far.
This is such a darn simple thing, a darn screw, that is stopping me from removing the shields.

I took a dozen pics just now, and here is one that came out clearer.

I agree it sure DOES look like some sort of Rivet or Brad, but that makes no sense. This same screw size is used on many different points, on the rear, and side Heat Shields. I am unable to get a clearer shot deeper into the small screw, but I can see some sort of angles in there, that some sort of bit must catch.
The side heat shields also have standard slot type screws one one end. Those are easily removable.
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Why Lopi wouldn't simply give me the size is beyond me. They know what it is.
They install probably hundreds of them each day/week. I am unable able to get the darn two side heat shields off so far.

My dealer will be sending someone up at some point - the problem is I am 2 hours from them, and it might be a week or longer.......... Which is why I am asking for help on this board.

I am really holding my tongue, (well fingers I mean!) as I know this site does not allow bashing of brands/dealers, but to say I am frustrated is a HUGE understatement.

I don't want to start drawing on the heat shields - yet, as Lopi's last contact to me was I could invalidate the warranty......if I left some little x marks all over the shields, I don't want that to cause issues......I need to figure out a way to mark them that 100% would come off, as this sure would be the simplest solution - a screw issue.

My Hearthstone Heritage, which a few years ago I talked about issues with it, which a couple of weeks ago was sitting on my Hearth, where this brand new Liberty sits now - and I moved to another portion of my house, is havin' a grand ole time laughing at me.......(have to see SOME humor in this darn situation)
 
Update on my Liberty problem.

I have been running the stove daily, as weather cools here in the Southern Rockies.

I have now ruled out the heat shields, and after starting many fires, and listening to the the bang many times, I now feel it's an issue inside the stove, somewhere around the area of the air tube assembly.

My reason for thinking this, is I stuffed the stove with Kindling yesterday, got a real hot fire inside quick and the bang happened when the heat shields were still cool to the touch, and to top was barely 150........it seems the temp of the interior of the stove controls the bang, not anything outside the main stove box.

I also loosened the slot screws on the side of the side heat shields - did nothing.

My Lopi dealer just contacted me saying they could get a tech guy up here tomorrow, unfortunately I have something I can't get out of tomorrow, so it might be a week or two or longer before I can get the stove looked at. As I live 2 hours out of town, deep in the Mountains, getting someone up here is an issue, that I can't really blame my dealer for.

*sigh*