Lopi Liberty keeps warping rear heat shield

[jkazak]

Stove is maybe 15-years old. The original shield was warped when I bought it (used). I ordered a replacement and the new one was a much thicker gauge steel...but by the end of the first season with it it has also warped. This is the shield inside the firebox that (I think) protects the plenum for the secondary air.

I've not pushed above its rated burn temperature so I'm a bit disappointed with this. Not sure I should replace it again. Is it in danger of burning through the rear plenum box...? There is a small gap now that heat can get past the shield....

Is this a problem... it's there for a reason...

 

[begreen]

@fossil any thoughts?

 

[jkazak]

Bump for advice....

 

[begreen]

I haven't seen this shield and it doesn't seem to appear on the parts diagram. Can you post a picture?

 

[jkazak]

It's shown here in the second illustration.
It's the large piece that sits against the back wall of the stove between the brick.

 

[begreen]

Ok, I saw that but wasn't sure it was a separate piece. This is the first problem I've read about with that piece. Based on it's location I don't think you are at risk of serious problems if you continue to burn even with the small gap.

Some options are to have a new one fabbed up out of stainless steel at a local shop and replace the old one or maybe to put firebrick in front.

 

[jkazak]

I believe the replacement unit was/is stainless....Lopi must be aware of the problem because the new one is probably 2x thicker than the original but didn't solve the warping issue.
I may try and contact them to see what they think....although Travis Ind. isn't very user friendly. It's very tough to contact a real person there.

 

[webby3650]

If I'm understanding you correctly. That part in the back isn't a removable piece, it is the secondary air supply channel. Lopi made a repair kit that was intended to be welded in to cover the original warped air manifold. It was simply a cover made from heavier steel that should have been welded in I'm pretty sure.

 

[jkazak]

First off - thanks for coversing with me regarding this issue.
This piece is removable - as far as I can tell. The original part wasn't welded either. There is a plenum that IS welded and connected to the upper chambers that send air through the secondary pipes and this piece sits in front of that plenum - sliding into "gaps" between that plenum and the brick.
When I removed the original part there were no signs of welds. When I ordered the replacement I believe they called it a heat shield. Hmmm...

 

[webby3650]

I've never seen a removable part on any Lopi secondary air manifold.

 

[jkazak]

Ok - further research indicates that this plate was/is a "fix" for warping secondary manifold(s) on the Lopi stoves. Seems that it should be welded in - but wasn't when I got this used stove. Hence my not knowing the replacement part I got was supposed to be welded and may be the reason it warped as well.
Being in the middle of burning season I'll probably continue using it as is and in the summer replace it (again) and cement a couple of hairline cracks in the upper air channels - apparently another common issue with these stoves. The cracks don't seem to cause a danger concern - from what I've read - and the performance isn't noticeably affected. Just yesterday the secondaries were blowing like a blowtorch when I reloaded and closed the main air supply. And the stove doesn't "run away" on me....although it seems to like being fed a lot.

Next summer I'll probably have to go through it pretty well and replace the door gasket as well. Installed a new gasket (2)years ago - I think. Does that seem right...?

 

[begreen]

Sounds like a plan. Maybe weld anything that is cracked while getting the plate welded in. Not sure if you need a factory plate unless it's inexpensive. It might be cheaper to have a local shop cut you one.

 

[webby3650]

Ok - further research indicates that this plate was/is a "fix" for warping secondary manifold(s) on the Lopi stoves. Seems that it should be welded in - but wasn't when I got this used stove. Hence my not knowing the replacement part I got was supposed to be welded and may be the reason it warped as well.
Being in the middle of burning season I'll probably continue using it as is and in the summer replace it (again) and cement a couple of hairline cracks in the upper air channels - apparently another common issue with these stoves. The cracks don't seem to cause a danger concern - from what I've read - and the performance isn't noticeably affected. Just yesterday the secondaries were blowing like a blowtorch when I reloaded and closed the main air supply. And the stove doesn't "run away" on me....although it seems to like being fed a lot.

Next summer I'll probably have to go through it pretty well and replace the door gasket as well. Installed a new gasket (2)years ago - I think. Does that seem right...?

My pleasure.

 

[tpenny67]

I have a Lopi Liberty bought new about 15 years ago with the same interior heat shield. It warped during the first heating season, so I got a new one under warranty and that one warped also. But it still functions as a heat shield and hasn't changed it's (warped) in a very long time.

From what the dealer told me, earlier versions of the stove didn't have this shield and the secondary air duct had a tendency to burn through with time, so they added this shield.

This shield just about always has flames right against it. The air entering in the front center of the stove burns a channel through the wood, and all the flame coming through that channel hits this heat shield head on.

 

[begreen]

Interesting observations. Wonder what makes the flame go strong in the back center? Normally the most intense flame would be forward in the firebox at the leading edge of the baffle. Is this intense flame at the top or the bottom of the firebox.

 

[tpenny67]

Interesting observations. Wonder what makes the flame go strong in the back center? Normally the most intense flame would be forward in the firebox at the leading edge of the baffle. Is this intense flame at the top or the bottom of the firebox.

Unless the air is cut way back, I usually get one set of flames off the primary air (the ones hitting the back of the stove if they can't find their way up through the wood, and then when they hit the secondaries on a fresh load there's another set of flames at the top heading towards the front of the stove.

If I cut waay back on the air, I'll get few flames on the bottom and a lot of secondary combustion, but it doesn't seem to last. It slowly dies down until it's smoldering without many flames anywhere.

The secondaries only seem to burn hot and consistent when the stove is going nuclear.

 

[begreen]

Usually the primary air comes via the airwash. Is there a boost air feed down low and front of the firebox

 

[tpenny67]

Yes, there's a small hump front and center that supplies some of the primary air. Put a few coals in front of it and it will literally blow-torch through any wood in front of it.

At lot of it also has to do with how the wood is loaded. On my current load (since my previous post), the primary flame is going under the front log, up the middle of the stove, and getting some secondary burn off the back and middle tubes, but not much off the front tube. Stove top is currently at 650. It's a nice fire by my standards.

When I first had the stove, I tended to dig an air gap in the ashes so the air could get under the logs. This produced the flame shooting at the heat shield and let to a very hot stove.

15 years and I'm still figuring out how to burn this thing

 

[begreen]

I'd be tempted to take mirror under the front of the stove and explore to see if the boost air has a separate air intake port from the primary air control. If draft is good and the wood is dry it may not be necessary. I blocked it off on our stove many years ago and have never missed it. Some folks have done likewise on the big Englander. Blocking it off turned the stove into a pussycat with longer more controllable burns. If you find the port it will probably be a small hole about 3/8 to 3/4" in diameter which can be blocked with a magnet.

 

[kversch]

Interested to see what you find. My liberty acts the same way. I'll have to check this out too

 

[tpenny67]

A mirror doesn't show much, other than a flat piece of steel that forms the bottom of the convection chamber with a hole in the middle for what is probably the secondary air intake.

The primary air (for both the air wash and the bottom center port) all seems to come from a hole right above the air control rod. As you pull the rod out, a sheet of steel gradually blocks off the air until it hits a stop screw which prevents you from blocking the air intake off completely.

From reading other threads on this forum, people have tried either using high temperature tape to reduce the size of the primary intake (thus allowing the secondaries to draw more air relative to the primaries), or removing the stop screw so the intakes can be closed completely. Of those two options, I'd be more inclined to try taping off the primary intake. It's sort of like changing the mixture adjustment on a carburetor: by reducing the primary intake relative to the secondaries, less smoke "fuel" would be produced relative to the air available at the secondaries.

To limit the air available at the front and center port would probably require making a sheet metal cover to block the intake inside the stove.

And of course the problem with all these approaches (excepting removing the stop screw) is that you really want these things to be adjustable to suit the current state of the fire. But this stove was intentionally designed to have a single control for all intake air.

It's all just theory at this point. It may be a few weeks before I have enough time at home to get a prolonged fire going and try taping off the primary intake. These things just won't make much difference on the first load of wood before a good supply of coals is built up.

If anybody else has a chance to try any of these things, please let us know how it went!

 

[Graeagle]

Stove is maybe 15-years old. The original shield was warped when I bought it (used). I ordered a replacement and the new one was a much thicker gauge steel...but by the end of the first season with it it has also warped. This is the shield inside the firebox that (I think) protects the plenum for the secondary air.

I've not pushed above its rated burn temperature so I'm a bit disappointed with this. Not sure I should replace it again. Is it in danger of burning through the rear plenum box...? There is a small gap now that heat can get past the shield....

Is this a problem... it's there for a reason...

Hi J. I am also concerned about the heat shield on the rear secondary air manifold. It's obviously there for a reason.. Mine is deteriorating. You mentioned that you have bought replacements. I have the same owners manual that you referred to. I don't see the heat shield nor do I see a reference or part number for the heat shield. Who did you order the part from?What part number did you use? Thank you in advance for any information.

 

[begreen]

Contact your Lopi dealer for the replacement part.