Questions about a Cemi Concept II

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hayjeff

New Member
Jan 7, 2009
4
Northern KY
Just bought a house with a Cemi Concept II insert installed so I'm just getting started with wood burning.

First, does this stove have a catalytic cumbustor? Everything I've read online indicates no, but the local stove shop tells me that it does. Naively I though if the lever above the door was just a damper one position would send smoke into the house, but it doesn't. Or does this just limit the smoke from leaving so it burns in the insert?

Second I bought a magnetic thermometer which I stuck on the face of the stove, above the door. What temperature should the stove operate? It gives a range of 250 - 475 as optimal but is this only correct for the flue and not the door?

Where should I build my fire? The stove already had a grate in the insert and I have been putting the wood on it. Should I remove it and place it on the bottom of the insert?

Finally, does anyone know if there are air quality issues with a stove like this? I understand the EPA began certification in 1991 and this is older than that. I have young children in the house.

Sorry for so many question but info on this particular stove seems non-existent. I really am interested in operating this stove safely and efficiently.
 

burntime

New Member
Aug 18, 2006
2,395
C'mon hunting season!
I had the exact same stove. I only close the damper when not in use? Open it when burning. There is no cat in it. The top shelf is kinda a preliminary reburn like the new stoves with out the secondary burn tubes. As far as issues...it puts out more pollution, and is not as efficient. Take the grate out, it will overfire it and reduce the output of heat. I never ran a thermometer but If I mounted one it would have been above the door. The old stoves are thicker and can take more abuse. My stove had the optional second blower...very few have 2. The only pain is I had mica windows and not ceramic so I had to replace those and the wood handles every 2-3 years. Take a handle to the hardware store and they can match them. Make sure you get wood, the metal will scorch you. As for heat output...they were not measured the same, the info I used to have on it said 109k btu's. I used to burn 5-6 cords of wood heating 3 cold months a year. Now I burn about 4.5 cords over 6.5 months. At first I used to put a timer on the plug to shut down the blower after 5 or 6 hours. To get an overnight burn you need to load it up a few times and get a BIG bed of coals, then when it is caught good damper it all the way down. The sooner you damper it down the more heat stays in the home. One last thing, this is a slammer unit with no liner, make sure you have good insulation around the surround or you will loose more heat then you gain. I can tell you that it is a good stove for its time but the new ones do a better job over a longer period of time! Good luck...
 

hayjeff

New Member
Jan 7, 2009
4
Northern KY
Awesome, thanks for the reply. Just to make sure I understand correctly, when you say damper down for an overnight burn are you saying close the damper over the stove with the single center lever above the doors or do you mean close down the the air intake with the two levers on either side of the blower output? Also, how would I know if I have two fans? I did notice the handle has started to feel weak. Good to know it is easily replaced. It does put out a lot of heat. Right now I can usually keep the furnace from kicking on. The upstairs rooms are a little colder but not unreasonable as long as the doors are open, nothing a space heater can't solve. Again thanks for the reply. It looks like I can still improve my usage of the stove.
 

burntime

New Member
Aug 18, 2006
2,395
C'mon hunting season!
Sorry, I should have been more clear, by damper down I mean the levers over the doors. I never choked the damper itself down except when I was not burning. The section under the door lip will either be one or 2 fans. Two is a good foot wide plus, a single is half that. You should unbolt the fan and clean it too, mine was caked with ash from not turning the blower off when loading!!!
 

hayjeff

New Member
Jan 7, 2009
4
Northern KY
I can't tell you how helpful this has been. I've been pretty much in the dark with this stove. I cleaned the fans, there were two. No too bad, but dusty and a little blockage. It would be my guess that the grate is causing me to lose heat as well. After taking off the fans, it looks like the air will pass under the bottom of the stove, where my coals will lie without the grate. It'll probably heat the air more. Thanks again.
 

burntime

New Member
Aug 18, 2006
2,395
C'mon hunting season!
You are 100% correct. No problem, glad I could help, thats what this site is for! Stay warm :cheese:

P.S. I hunt in your neck of the woods for deer, Bath County, Owinsville I believe!
 

acrausaz

New Member
Jan 16, 2009
4
Northern Ohio
hay_j
I have the same exact insert and I began using it last winter (2007). It's actually a really well made unit and was quite advanced for it's time. I found the manual online so you can read up on it yourself, I will post the link for you. In a nutshell burntime was mostly right, but not totally right. You WILL want to CLOSE the DAMPER once you have a hot fire going, approx. 1 hour after starting up cold. I only open my damper when I put wood in so no smoke gets in the house, the rest of the time it's closed unless I'm starting a fire cold. It actually tells you this right in the manual. With the damper closed you get what the manual calls "second level combustion". It's more efficient and you will get more heat output per unit of wood you are using. You can actually see this working when the insert is hot, the flames will look like they are moving in slow motion, very slow looking. It's hard to explain, but when you see it you'll know what I'm talking about. The little handles on either side of the hood are the "air intake draft regulators". They are what let the oxygen rich air into the combustion chamber. If the handles are all the way up then you will get the hottest possible fire, but will burn wood at a slightly faster rate. I load this thing up at night and open the regulators half way and like I said before, the damper is of course closed (as it should be almost all of the time). In the morning 6 or 7 hours later I still have cherry red hot coals and a slight bit of wood left burning. I've been able to keep hot coals smoldering in this unit for over 12 hours with the regulators closed all the way. It's not quite as hot, but last longer. This is the trade-off you have to make. The wood only has a limited amount of energy in it. If you want a hotter fire, it will burn faster and you'll have to put wood in more often. Although from my experience it's not THAT much more wood. Maybe 15% more roughly speaking. You are also right about the grate, there shouldn't be one. Build the fire right on the plate in the bottom of your unit. The link I'm giving you has nice diagrams in it and you are right about the fans, they blow around the firebox and out the top of the unit. Right now I'm looking at putting higher capacity fans in. The owners manual said with a dual fan setup you move 210cfm of air. I think I can do better. It was a bit long winded, but I hope this helps. Any other questions just ask. Here is the link to the owners manual and sales brochure. It's in a .pdf format, you have to have the free Adobe reader on your computer to view it if you don't have it already (you probably do, it's very common). Copy and paste the following in to your address bar in your browser.

http://homeappliance.manualsonline.com/mdownloads/267de2ef-a8b8-4557-b19c-4199fbdefe0d.pdf
 

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burntime

New Member
Aug 18, 2006
2,395
C'mon hunting season!
Wow, I inherited it from my parents and it was run wrong for 20 years!!! I remember asking about the damper and was always told to not do it? O'well, whats an extra cord a year ;~)
 

hayjeff

New Member
Jan 7, 2009
4
Northern KY
Wow, I can't believe I actually have the manual now. I didn't think I would ever see it. Thanks so much. I read the operating instructions and it was very helpful. I did have one question concerning air quality. I get the occasional puff of smoke in the house, mostly from my learning how to operate it, but should I be concerned with air quality. I have three children. I can occasional smell a fire smell but mostly after a reload. Last night the temp dropped to 0 and it seemed liked the entire first floor of the house smelled that way. My rule of thumb is if you smell it your breathing it in. I did noticed there is a small section (~1 inch) of gasket missing that I am replacing today. Could that contribute or are there techniques to eliminate any pollution in the home? I assume I shouldn't smell anything except right after the door is opened. Thanks for the help and all the information.
 

acrausaz

New Member
Jan 16, 2009
4
Northern Ohio
@burntime

I wouldn't say that you were wrong, I'm just going by what the manual said. If I wouldn't have seen it in there with my own eyes I never would have believed it. When I first fired it up I didn't know anything about it at all. The damper was closed and I couldn't figure out why when I was trying to start a fire smoke was pouring in. I didn't even know that it had a damper, I thought my chimney was clogged! LOL! My dad told me to open the damper and keep it that way if I wasn't burning wood. I ran it like that for about 3 weeks before I found the owners manual online. I've never had an insert before, but other people I talked to that had one (like my dad) told me to always keep the damper open. I wonder if it's actually supposed to be shut on other inserts too? I know they are all different, but I wonder if people are running other model inserts the wrong way? Just wondering to myself out loud. BTW an extra cord a year is a LOT of work!!! lol. :). Do you have the literature on your insert? Just wondering if your model is run this way too? Post back when you have a chance, I'm really curious about how other inserts work because I plan on moving in a couple of years and I will DEFINATELY have a fireplace with an insert again. I love it!

P.S. Hope your staying warm up there, you guys are even colder than we are right now!!!
 

burntime

New Member
Aug 18, 2006
2,395
C'mon hunting season!
I HAD the exact same insert with the dual fan. My parents bought it in 1980 or 81, they ran it until 1999, I bought a home and was set to buy a quadrafire and stopped at their home on the way to check thickness of metal etc to compare. My dad was there and said take ours, its more than paid for itself and we are going to gas! I ran it for about 5 years in my home and finally bought a hmapton HI300. I had asked about the damper multiple times and my parents alw2ays told me that it was to be open. I had some literature with it but only the picture of the airflow and the install guide. They paid 1800 in 1980ish, it got 25 years of service, and I sold it for 300 bucks with an extra set of mica windows. It was a great unit, I just wanted to upgrade to a more efficent unit and different looks. If your on a budget and you have one burn it! If you can afford to upgrade, you will be suprised at how much nicer most of the new ones are! Not knocking it, but the cemi is a semi on a racetrack if you know what I mean. It takes a while to get going, and you can't control it real well. Its a off or full tilt type of stove! :)

BTW, I had to remove and reinforce the top plate 2 times in the 25 years. The heat would make it belly to the point it was down 3 inchs and taking firebox space.
 

acrausaz

New Member
Jan 16, 2009
4
Northern Ohio
hay_j said:
Wow, I can't believe I actually have the manual now. I didn't think I would ever see it. Thanks so much. I read the operating instructions and it was very helpful. I did have one question concerning air quality. I get the occasional puff of smoke in the house, mostly from my learning how to operate it, but should I be concerned with air quality. I have three children. I can occasional smell a fire smell but mostly after a reload. Last night the temp dropped to 0 and it seemed liked the entire first floor of the house smelled that way. My rule of thumb is if you smell it your breathing it in. I did noticed there is a small section (~1 inch) of gasket missing that I am replacing today. Could that contribute or are there techniques to eliminate any pollution in the home? I assume I shouldn't smell anything except right after the door is opened. Thanks for the help and all the information.
I know how you feel about the manual, I was so happy when I found it I wanted to do backflips! As far as the smoke in your home, there shouldn't be any. The first thing I was going to ask you was about the seals around the doors, but you already answered my question. Replace them right away and I'm going to bet your tiny smoke problem is gone. Like I said in my previous post I do open the damper before I open the doors to load more wood in it especially if it's not hot or I just started a fire. Doing that should help cut back on smoke. I have kids in the house too, so I'm as careful as possible. I don't think it's possible to completely eliminate 100% of smoke from your home since you have to open the doors occasionally, but if the doors are closed you shouldn't notice anything. Do you actually turn the lock on the doors when you shut them? This is somehting else you should always do. The latch is adjustable with a wrench if it doesn't seem to close tightly enough. You want a good tight seal around the doors, but don't adjust the lock lever arm too tight because you'll damage the seal and have to replace it again. I adjusted mine until there was no play at all in the doors, but I don't have to turn my allen wrench hard to lock the doors, I can do it with two fingers and a thumb using the small end (almost no leverage). Locking the doors is also a precaution against a downdraft if it's windy outside. It's possible that if the doors weren't locked a strong gust of wind could blow the doors open and blast hot wood/ coals out of the box. We don't want that!!! I'm not sure if you actually saw smoke lingering around your downstairs or if you just smelled it. If you didn't see anything it's also possible you were smelling smoke that got into furniture, carpet, drapes or any other kind of cloth or fabric. That smell will linger forever if you don't get things washed and cleaned. I know because I smoked myself out a couple of times when I was first learning to operate my insert. :-(. The smokey smell was terrible.
 

acrausaz

New Member
Jan 16, 2009
4
Northern Ohio
burntime said:
I HAD the exact same insert with the dual fan. My parents bought it in 1980 or 81, they ran it until 1999, I bought a home and was set to buy a quadrafire and stopped at their home on the way to check thickness of metal etc to compare. My dad was there and said take ours, its more than paid for itself and we are going to gas! I ran it for about 5 years in my home and finally bought a hmapton HI300. I had asked about the damper multiple times and my parents alw2ays told me that it was to be open. I had some literature with it but only the picture of the airflow and the install guide. They paid 1800 in 1980ish, it got 25 years of service, and I sold it for 300 bucks with an extra set of mica windows. It was a great unit, I just wanted to upgrade to a more efficent unit and different looks. If your on a budget and you have one burn it! If you can afford to upgrade, you will be suprised at how much nicer most of the new ones are! Not knocking it, but the cemi is a semi on a racetrack if you know what I mean. It takes a while to get going, and you can't control it real well. Its a off or full tilt type of stove! :)

BTW, I had to remove and reinforce the top plate 2 times in the 25 years. The heat would make it belly to the point it was down 3 inchs and taking firebox space.
I wonder if the one I have wasn't used much, I removed it to clean it before this season and gave it the once over and it looked great. This is only my second season using it and so far the top plate looks okay. I have my fingers crossed! :). I know the new inserts are awesome, my parents have one, not sure what kind, but they paid several thousand for it, and it's pretty amazing. The blower alone puts mine to shame!
BTW where did you get the mica glass at? I want to replace mine. I looked in mcmaster carr and couldn't really find anything.
 

pam_candelaria

New Member
Jan 25, 2009
1
Aurora CO
We just bought a home that has the Concept II insert as well, and I wanted to thank everyone for all the great info!! I searched online and didn't find much, and am thrilled to have found this site- especially the link to the owner's manual! The Denver Metro area seems to have woodburning bans when it's coldest so we'll be using this more as an occasional fireplace than a heat source, but it is still great to know how it works. The people who had our home before weren't all that great when it came to home improvements or maintaining what they did have, and I am glad to have good info on maintenance and operation so I can light a fire with confidence that I'm not going to burn my house down. Thanks again!
 

burntime

New Member
Aug 18, 2006
2,395
C'mon hunting season!
Sorry fr the delay, I bought the mica at a fireplace store...Its not cheap, I think its about 40 bucks a window and then about 20 minutes dinking around per window to install...
 
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