Osburn 1100 Install

[RobbieB]

Well, here it is, the long convoluted tale. How I got the insert in a zero clearance.

This is intended to be just my tale of my install. I'm not suggesting anyone follow my lead as it's probably not to code. In other words, entertainment value only. Again, I'm not heating my house with this thing, I don't order firewood by the cord, I get small bundles at the grocery store from time to time so I can enjoy the dancing flames without sucking all the heat out of my house. Romance and ambiance!

The beginning;



A Marco DWF 36. Circa 1984. When I bought the house in 89 all the refractory was cracked and I replaced it. A fireplace store in San Jose had it in stock. Now it has to be custom made. Before the install I hired a sweep to clean the flue (8 inch steel inside 12 inch steel) and he found the flue in good shape, very little creosote and he was amazed that the damper was still intact, said a lot are rusted out from rain. Only repairs needed were cracked refractory, $500.

The fireplace was installed on a slab in it's own alcove / chase;



The dryer vent is the outside air supply to the fireplace. I got busy with the plasma torch;



The idea was to replace the bottom refractory with bricks and add bricks to the hearth and bridge with a steel sheet pan and slide it right on in;



But it didn't install. It slid in just fine, but there was no way it was going to connect to the flue liner. I bought the double wall flex liner kit from the Osburn factory site when I ordered up the insert. Yes it's flexible, but not that flexible. The despair started big time. This thing will not work and I've just destroyed my fireplace. I'm going to have a big ugly hole in my house forever. I need help.

So I called up a install house. Sold inserts and installed them. Cool, go to the pros, they know what to do. I don't care how much it costs, a few grand is OK and way better then this hole in my house. They told me you can't install an insert in a zero. They wanted no part of it.

OMG what have I done?

Going out for lunch, more later.

 

[kennyp2339]

I'm with the pro's on this...want nothing to do with this thread, the only reason why I'm participating in this is to ask you kindly, when you sell your place rip this unit out so an unsuspecting family doesn't get hurt / killed due to this negligent install. You may be ok with burning a bundle here, bundle there, but someone new to this specific unit might have other plans and try to use this full time.

 

[bholler]

This is intended to be just my tale of my install. I'm not suggesting anyone follow my lead as it's probably not to code. In other words, entertainment value only. Again, I'm not heating my house with this thing, I don't order firewood by the cord, I get small bundles at the grocery store from time to time so I can enjoy the dancing flames without sucking all the heat out of my house. Romance and ambiance!

You need to stop using that insert now. If you had just put the insert into the fireplace without altering the fireplace it would not be to code but as long as the fireplace was installed correctly and was still in good shape it would probably be safe. But you completely changed the fireplace it no longer has air moving around it to keep the outside of the box cool it no longer has the refractory panels in it which also help keep the outside cool. It is dangerous and even the way you are burning it you could still very easily burn your house down.

Please stop using it now.

 

[RobbieB]

Oh yeah, that's a given. I don't think it would pass the required inspection. Put some trim on the sides and a wine cooler in there -

No plans to move, I like it here. Been here 28 years now, house is paid for, has had good upkeep, new roof, high efficiency furnace and AC and I put a 3.6 KW solar array on the roof last year.

OK. Now I'm on my own. And I can think again. The flex is just not going to bend to the insert outlet in the space I had, but a 45 degree elbow would. I needed to get as much space as possible and those full size bricks on the hearth were too high. I needed to bridge the frame of the fireplace too. I may be crazy but I'm not crazy enough to cut the frame. So I removed the full bricks and mortared in "half high" bricks;



Also cut the bottom out of the FP and saw the slab. Which I really wanted to see. The insert weighs 300 lbs and I didn't think it was a good idea to rest it on the sheet metal of the FP. I put 8 bricks right on the slab, made a sheet metal form and poured and troweled 25 lbs of mortar on top;



3 inch wide steel bars with 1.5 inch wide backers welded bridge the hearth bricks and the slab pedestal. I leveled it and mad another 22 gauge steel pan to cover it all and it was now "liner connect" day. I got up on the roof and shoved the anaconda down the flue;



This was not easy. It's really not that flexible. Then I rivited the 45 degree elbow on and pulled it back up to the top of the FP and slid in the insert and made the connection. The fittings are all 304 stainless laser welded;



The telescoping section made it easy to slide up to the elbow and I rivited it in place. This was a happy day and over 2 months since I started. The next day I installed the flue cap;



You can see the 8 inch to flue liner adapter. Tested by many storms recently and no leaks found.

Time to walk the dog, back later.

 

[bholler]

You can see the 8 inch to flue liner adapter. Tested by many storms recently and no leaks found.

Is the air still able to circulate through the outer sections of the old chimney? Is there insulation on the liner?

 

[kennyp2339]

Is the air still able to circulate through the outer sections of the old chimney? Is there insulation on the liner?

Some people don't get it, best you can do is pray for them.

 

[RobbieB]

The entire flue system of the FP (except the damper) is intact. The entire top of the FP is intact except for the baffles that directed the fire to the flue. The top of the chimney system is intact except for the removal of the flue cap which I gave to my neighbor as his was rusted and destroyed. A 6 inch SS double wall flex liner was pushed all the way down the existing 8 inch flue. Essentially now I have a triple flue, no insulation except roxul packed into the gap where the 6 inch flue exits the 8 inch inside the FP.

I'm getting less heat on the drywall above the fireplace with the insert than I did with the FP before.

Ok, now the fun part, the surround, but first there was the issue of the outside air control, a lever that would not be accessible once the surround was on so I made an access;



A bracket with a screen door roller and a beaded chain to the lever secured by a binding post.



The insert sits in the opening 1 inch further than stock but here I got lucky, the factory surround had a one inch lip for the trim kit (which I'm not using) so I cut it off and used this stainless steel edge trim instead. And I wasn't going to leave that blower cord on the hearth either so I made a wire channel to protect it.



Next time I fire it I'll stick a meat thermometer probe in the mortar channels in the bricks on top the surround and see how warm the space inside gets. The surround gets warm in operation, but not hot, nothing that will burn your finger like the stove top will. The space is vented by the bottom of the surround as well as the mortar channels.

We shall see.

 

[bholler]

So you completely covered the air circulation vents for the fireplace that keep the outer shell cool also???

Seriously are you trying to burn your house down? I hate to be so harsh but your install is so far from what it should be I don't know how else to respond.

The top of the chimney system is intact except for the removal of the flue cap

Yes but are the air vents that allow cooling air to circulate between the layers of the chimney still exposed?

The entire top of the FP is intact except for the baffles that directed the fire to the flue.

Yes but the bottom that supplies cooling air to the top is gone as are the refractory panels. And the vents are covered anyway so you have absolutely no cooling of the old firebox at all.

 

[RobbieB]

That's why I put this up, so I can get feedback from you guys.

I can always vent the surround more at the bottom and the top. Some Greenlee punches and a wrench. The flue has never been vented, it's sealed at the top and also at the top of the chimney.

I'll find out how hot the space is behind the surround at every mortar channel next fire. I can also remove the surround and place a bunch of thermocouples all around and burn again to see the temps at the back of the FP.

I really enjoy this feedback, I really don't want to burn my house down -

 

[kennyp2339]

I wish I could add something positive, but I don't have any experience with altered, untested installs (not even certified for legit installs) I wish you best of luck and safety.

 

[bholler]

That's why I put this up, so I can get feedback from you guys.

Well you have my feedback. Stop using it at this point you have destroyed the fireplace and the only way to make it safe at all is to tear the whole thing out and start over.

 

[SterlingSL]

I'm lost - what has he done that is so dangerous? I have found through my install that installers don't really know what the hell they're doing anyway. Looks like nearly the same thing that was done in my house by a 'certified' installer/sweep.

Case in point: if you look at my recent thread - my install was quickly out of code with no insulation on my liner. I had to argue with them to let me put insulation on the liner they already installed based on advice I received here.

 

[bholler]

I'm lost - what has he done that is so dangerous? I have found through my install that installers don't really know what the hell they're doing anyway. Looks like nearly the same thing that was done in my house by a 'certified' installer/sweep.

First off he installed an insert into a fireplace which does not allow inserts to be installed in it. Next he removed the refractory panels which help insulate the out sside of the firebox. Then he cut out the bottom of the firebox which completely destroyed the convective cooling passages in the firebox. Then he covered the vents which meant that there is absolutely no air moving through the old fireplace to keep the outside cool. There are probably more problems we don't know about but those are plenty to cause a catastrophe.

 

[bholler]

Looks like nearly the same thing that was done in my house by a 'certified' installer/sweep.

Yours is a metal heatform in a masonry structure with a masonry chimney his is a zero clearance unit in a framed structure.

 

[fishki]

So I am curious, if all you are after is 'Romance and Ambiance' why go thru all this trouble? Why not simply repair what you had, put some glass doors on and be done with it?

Instead it looks like you have created a fire hazard by destroying the the old fireplace and forcing this to fit where it does not belong.
Apparently you know this is not to code yet you insist on going thru with this install regardless of your safety or the safety of others.

 

[blacktail]

What do you think your insurance company will say if this insert causes a fire?

 

[begreen]

It looks like the install was well intended but it went seriously off the rails. Now it's a textbook case of how not to install an insert.

 

[RobbieB]

OK, time for a little testing. Thanks for the tips re pyrolysis and the lack of venting the space.

I ordered up the Greenlee punches, a laser infrared thermometer, a 4 channel thermocouple meter and a bunch of probes and couple wires and a CO meter. Already have a smoke / CO alarm but the meter will give me a readout. Also a smoker thermometer to track the temp at the hottest point behind the surround permanently.

But first I wanted to see what I had with what I have now so lit up fire number seven.



In 45 minutes it got to 450 F stovetop and the blower kicked on and reduced the temp a bit.



The hottest part of the surround was right in the middle of the top (no surprise) and it was easy to verify the gradient with just my hand. Cool at the bottom and warmer at the top and the top was the hottest right in the center. Here's the temp of the air behind the surround when the stove top was ~430; 157 F with a meat thermometer



The hottest it got was 170 when I got the stovetop to 500.

So the next step will be punching a dozen 1.375" holes in the surround 3 each low on the legs and 6 in the top and install the "smoker thermometer right in the middle of the top. Before I mount the thing I'll place the thermocouples around the inside and a couple in the space between the bottom of the FP that I cut and the slab. Then I'll burn again and see what the vents do with and without the blower.

The data I got today causes me not to worry, but the added ventilation will help if the blower (or power) fails.

When the stuff gets here and I get it installed I'll post the final.

One test is worth a thousand expert opinions.

 

[bholler]

One test is worth a thousand expert opinions.

And what is a safe temp inside a severely compromised zero clearance fireplace? Do you know what temp pyrolisis occurs at? Do you know what temp pyrolized wood can ignite at?

There is no amount of measuring temps you can do that will make your install safe. You have to allow for worst case scenarios like chimney fires or runaway stoves ect.

By the way we are not worried about the surround of the brick face at all. What is concerning is the wood framing surrounding the old fireplace inside that structure. Have you even inspected the setup to confirm that there are proper clearances to the old unit?

 

[RobbieB]

I can tell you that the old unit ran hotter than this does. I had the metal frame with the glass doors and the chain curtain thing installed. The surround got a lot hotter than this one does, it would burn you if you touched it. You could feel the heat on the drywall above the FP. You could get a lot more wood in there and it would roar going up that 8 inch flue with an unlimited air supply. The creaking of the hot metal as it expanded was often.

I hired a professional sweep/inspector before this install as advised. He found the flue very clean, no rust, the damper and structure good and the only repair quoted was the cracked refractory (bigger than 1/16") which needed to be custom made.

Yes, I read that the pyrolysis occurs at 212 degrees for wood and I'm a long way from that. The heat I measured has to go thru 2 sheets of steel with insulation between to get to any wood. I'm not worried now and if the venting tests good I'm not going to worry at all.

 

[bholler]

I can tell you that the old unit ran hotter than this does. I had the metal frame with the glass doors and the chain curtain thing installed. The surround got a lot hotter than this one does, it would burn you if you touched it. You could feel the heat on the drywall above the FP. You could get a lot more wood in there and it would roar going up that 8 inch flue with an unlimited air supply. The creaking of the hot metal as it expanded was often.

Yes but where was that heat directed and where was the unit protecting?

I hired a professional sweep/inspector before this install as advised. He found the flue very clean, no rust, the damper and structure good and the only repair quoted was the cracked refractory (bigger than 1/16") which needed to be custom made.

But did he pull the chase cover and check for proper installation? He really should have

Yes, I read that the pyrolysis occurs at 212 degrees for wood and I'm a long way from that. The heat I measured has to go thru 2 sheets of steel with insulation between to get to any wood. I'm not worried now and if the venting tests good I'm not going to worry at all.

It can occur at temps a little lower than that but 212 is a decent starting point. now how long were you burning when you measured? Where did you measure? What happens if you have a chimney fire? You have to think about all of these things.

I just want to be very clear to anyone reading this who cares about their home or their safety. This install is not safe at all

 

[RobbieB]

The fire in the fireplace just basically went up the flue, you know how they work. Until you got like 2 to 3 inches of glowing embers on the bottom you get no heat. A lot of BTU's just going right up the stack.

Yes, I did remove all the refractory and cut right through the bottom to the slab, but then I bricked and mortared up the hole and bridged it to hearth which is also bricks on the slab. I removed the baffles that directed the fire into the flue, but not the insulated double sheet metal walls of the prefab. The insert is on a very strong, stable and fireproof base.

Now to the heat. The insert is box in a box with blower driven space between. Even w/o the blower it's still vented bottom to top by convection. The insert burns way less fuel than the FP and is draft limited, not to mention 75% efficient. I consider that half the fuel and 75% of that going into the room instead of up the flue means that the existing structure is only seeing an eighth (12.5%) of what the pre-fab was dealing with.

Again, I'm not suggesting that anyone follow my lead. It's not my intent to start an argument, just a report on my install. As they say on stunt shows "don't try this at home kids", the risk is mine and mine alone. I don't burn unattended and stop fueling well before bedtime. I will never leave the house with an active fire. I'll only go to bed after the blower shuts off automatically (stove top below 200) and I have a dry chemical extinguisher close.

But I'm going to continue using my Osburn because I love it. It works good and it looks good. It starts easy and burns clean. I see smoke out the flue until stove top hits 300 and then it's just "heat waves". The paint smell is gone. When I shovel the ashes that's all that's there. No little charred wood ends, nothing but ash. Sweet -

 

[blacktail]

Your insurance company might like to see all your instal pictures.

 

[bholler]

Well I am done trying to convince you that you are putting you house and life at risk with this setup. You obviously have no clue at all about the dangers you are dealing with and don't care in the least. So I hope everything is fine but I am not going to bother trying to save you from yourself anymore.

 

[NateB]

OK, time for a little testing. Thanks for the tips re pyrolysis and the lack of venting the space.

I ordered up the Greenlee punches, a laser infrared thermometer, a 4 channel thermocouple meter and a bunch of probes and couple wires and a CO meter. Already have a smoke / CO alarm but the meter will give me a readout. Also a smoker thermometer to track the temp at the hottest point behind the surround permanently.

But first I wanted to see what I had with what I have now so lit up fire number seven.

View attachment 195230

In 45 minutes it got to 450 F stovetop and the blower kicked on and reduced the temp a bit.

View attachment 195231

The hottest part of the surround was right in the middle of the top (no surprise) and it was easy to verify the gradient with just my hand. Cool at the bottom and warmer at the top and the top was the hottest right in the center. Here's the temp of the air behind the surround when the stove top was ~430; 157 F with a meat thermometer

View attachment 195232

The hottest it got was 170 when I got the stovetop to 500.

So the next step will be punching a dozen 1.375" holes in the surround 3 each low on the legs and 6 in the top and install the "smoker thermometer right in the middle of the top. Before I mount the thing I'll place the thermocouples around the inside and a couple in the space between the bottom of the FP that I cut and the slab. Then I'll burn again and see what the vents do with and without the blower.

The data I got today causes me not to worry, but the added ventilation will help if the blower (or power) fails.

When the stuff gets here and I get it installed I'll post the final.

One test is worth a thousand expert opinions.

Yes but this is one possiblity of a thousand. I thought of going cheap on my boiler install, but from reading here I decided to do it right. Over this winter I was glad that my mistakes were scarry, but not dangerous to my building.

That's why I put this up, so I can get feedback from you guys.

I can always vent the surround more at the bottom and the top. Some Greenlee punches and a wrench. The flue has never been vented, it's sealed at the top and also at the top of the chimney.

I'll find out how hot the space is behind the surround at every mortar channel next fire. I can also remove the surround and place a bunch of thermocouples all around and burn again to see the temps at the back of the FP.

I really enjoy this feedback, I really don't want to burn my house down -