Burn in Jotul 450

You can run the stove up to 650-ish to get more heat output.

The stove can be mounted either flush or 4" out. One thing that I am doing in the next couple of weeks is moving the stove out 4" - I need to extend the hearth out first.


jeff

Cityevader, Glad to hear your making some headway. Let me know how the rock wool works out for you, I think it will help. I am not trying to heat below where my stove is but my stove is at one end of my basement rec-room. The open stairwell is at the opposite end of the house, and the stat is in the center hallway. So all in all I am real impressed with the heat output given what the temperature and the wind conditions are. The brick around the whole face of my fireplace is very very warm to the touch, but noticeably cooler when you go above where the block off plate is installed.

Stihl and cityevader (and anyone else who can't get the heat up)

Don't give up on us now - we are going to get these unit working.

First - don't let "5 inches" of ash accumulate - keep it below the intake. I have to shovel some out each day, and I move it away from the intake to prevent clogging. I burn 5-8 hours a day, and remove a 2 gallon pail a week. The firebox needs the space in it to allow air to circulate, or it won't burn well - it is a small box, as we know.

Stihl, how hot are you getting the unit? - I get mine up to 750*F before the fan comes on (15 mins is what it takes me with dry wood), and I keep it there when I burn. If you can hold your hand in there, then your flue temp is low, and you aren't running the stove hot enough. I can't hold my hand inches from 750*F metal for long. As a millwright, do you have access to good IR thermometer? If so, take some temps and fill us in.

As for the science of the block off plate - once you get the heat (it doesn't sound like yours is getting hot) you will have convective leakage up the flue. The top may seem tight, but it likely isn't air tight. I know my flex fits thru the collar at flue top and has gaps in it - I would have to seal it with stove cement to make it air tight. The brick isn't an airtight seal - ideally it is very close. With the high temps inside the flue, the 800-1000F steel liner is going to heat the air and cause it to move (stack effect). It will create it's own circulation, just like a house will if it leaks at top and bottom.

A brick flue isn't an air tight unit - Many have two sets of liners (one for oil and one for your insert). If you have a clean out door, then air will enter that door and leave out the top of the oil side (You could pull a string from top to bottom). That air will cool the liner as it circulates. Yours sound like a single flue unit, so this leakage source may not apply. My flue had an old oil boiler in it, and the tiles an that side were wrecked, so air entered the flue thru the boiler and the clean out, and mixed around the stainless liner side. Then it exited thru the oil flue top. Oil is now gone, clean out stove cemented shut, and the top covered over.

Even if the brick flue was airtight, there would be rising and falling air along it's length as convective currents build, with hot air rising from the stove until it reaches an equilibrium temp, then falling down to be heated by an increasing temp of the liner and more warm air from the stove. The air at the top inside the chimney will be colder than the air further down that has the advantage of being closer to the stove and protected from the elements. This cold air will fall (actually be displaced by rising warmer air). This occurs around your liner anyways regardless of a block off plate - the block off plate makes it a closed system, keeping the airspace inside the chimney separate from the airspace inside the house envelope. This is my very poor description of convective circulation that will occur inside any chimney around a steel liner. I hope it helps.

So, in the end, get it hot hot hot, keep the ash from building up more than an inch, and see what you get.

Here is a post I built on how I get my fires going - those posting here have already seen it, but those silently reading at home may not have, so here it is again - https://www.hearth.com/econtent/index.php/forums/viewthread/31393/

Keep warm. We have 30cm of snow and 100km winds on the way in the Maritimes. Brrrr.

Another comment - if you can't get the stove above 500*F, then I would suspect wet wood. Iknow, Iknow - your wood is dry - hear me out.

I have some wet wood in my pile that measures in at 30%. When I stick it in the stove, my temps stall at 500*F until it gets kiln dried, then they run back up to 750*F. So see if you can get 750*F out of it, with the fan on high. I can with my dry sticks, I can't with my wet stick.

Somehow, it always comes back to the wood eh?

Rudyjr and I have discussed the wet wood issue offline - we came to the conclusion that EPA stoves, and the Kennebec in particular are really picky eaters when it comes to moisture content and the need for small split soze (2-4 inch ideal once heated up) - that is the trade off between clean heat and easy heat I guess.

Anybody else notice how picky the smaller firebox EPA units can be with moisture content and small split size?

Brent. My insert is hitting 750 to even 800 F. Thermometer mounted on top, center 4" back from door edge. You should know as you installed your own, that the main stove body has a galvinized sheet metal surround both sides, top, and back, that has pretty tight seams. It is spaced approx 1" on the sides and 1.5" on top air gap and guess what that gap does? I'd call it insulation. That is why I can get my hand in there. That is why the Heatalator ain't absorbing any heat as it would from the Elmira. That is also why my garage bricks ain't getting hot. That is also why I don't expect a drastic difference from the block off. And yes I have access to a high end IR thermometer and own a Princess Auto IR (I tested them agaist each other and close enough). I also have access to a Calibration Lab at my job site. Also it is a dedicated flue with no clean out etc. P.S Just checked with the IR thermometer: Stove top approx 700F Shroud surface 160F, and back wall of the hearth/heatalator 120 F. So the way I see it, I'm trying to stop the 120 degree air from going up the flue.

What is the temp of your liner? The liner should be hitting the same 750 - 800 temps. That air is going to rise. That is the source of the convection that I refered to in my post. Good luck - I don't think I can add any more value to help you.

Brent: The liner is around 155 F ( about 6" up) with the stovetop at approx 540 F. Thank You!

Cityevader, And anyone else who reads this. Brent knows what he is talking about. The first 3 or 4 fires I set in this stove were total failures. You need a good base fire to get the temp up from then on it is pretty simple. In my case I was just dong it the way I had done it in the past. Get the fire started, with the air wide open, throw a couple of decent size splits in. (watch the stove smolder) In my mind I was thinking not enough air. After talking to Brent I built a much more substantial initial fire, stove heated faster, threw a couple of smaller splits on. From that point on I had to work to keep the air low enough and the heat down. Right now it is 7 degrees in central Ohio and the wind is still 30-40+mph. I am typing this up in my home office, far end of the house, in a t-shirt, jeans, and bare feet, its too hot in the rec-room. Thanks Brent for your help.

Just rekindled my stove and with the air about a 1/3 closed, stove top at around 400 F the liner is about 1/2 (189 F). The Calibration guy at work tell me that some IR thermometers get messed up by different surface colours ie shiny chrome, maybe pretty shiny stainless? Anyhow, if the stove is going to be a heat exchanger it won't be MORE efficient if I have 500 F at the chimney cap. Check out the flue temp of this Blaze King Cat, don't think too many people have problems with this one, my buddy was in the market for one (a new stove) and was told these are the best!) http://www.youtube.com/watch?v=dwNYI6ME7kA
You would think the more heat that stays in your fire box, the more heat you get out!

Stihl, Post some pictures of your particular installation, fireplace, chimney,stove etc..., Maybe Brent or someone else can pick up on something. Thanks, Jim

Something is really wrong here. If your insert is hitting 750 to 800 F and you can stick your arm into the opening above it something is really, really, really wrong. The back side of my brick chimney is also in an attached garage, I have an UNINSULATED block off plate (but have the top 3 feet of my chimney insulated with mineral wool) and I can feel the warmth radiating off of the chimney in the garage. Yeah, I'm sure a block off plate will help your situation but it sounds to me like there may be more to it. There is not doubt that your stove top vs. liner temps are strange and yes, the IR thermometers are picky about shiney finishes. Next time you pull your surround off hit the liner with some high temp black spray paint. It will give you a similar surface to measure with your IR. Also, have you pulled your fan assembly and looked to the back of the stove under the doors? Is there creosote build up in the bottom? It can fall down the flu onto the baffle and end up in the bottom of the stove blocking airflow to the secondary system. Dont give up yet, this thing will cook me out of my 1300 sq. foot house.

Boostnut, I agree there has to be a logical explanation to this. Too many people have been able to get this stove to heat extremely well. In our house the only complaint has been that it is too hot at times, never thought I'd hear the wife say that! I need some practice at regulating the heat better. Maybe when we see some pictures someone will be able to pick up on something.

Boost nut:
I've checked the inside passages with a Boro-scope and all is clear.
Now if I can have everybody's attention here and thinking caps on: When I say the stove top is 700F and I can stick my hand between the Mantle and the stove, Let's not forget the shroud around the entire stove, to direct heated air out the front is what is protecting my hand from roasting. (shield is around 200 some thing F) Like the heat shield around the Catalytic of you car, and the heat shield on your motorcycle muffler etc. It is also why I believe the "block off plate" doesn't have a lot of convection to stop>But I seem a little outnumbered here. Maybe when I get a chance, I post a live "you tube" of the stove top, the IR temps, me sticking my hand in and holding it there, so you don't think I'm heavy on the "crack pipe" or something. Cheers guys, Mike

What I don't understand is that the liner is right there, above the shroud, and it should have a temp of at least 500 F if you have a 700 F stove, and I can't hold my hand next to 500 F steel. That is what we are unsure of. I understand that the shroud is cooler. But the liner best not be that cold - a 200F liner is a creosote magnet with a fresh load of wood. Based on your observation of not feeling any heat from the brick, I'm thinking that the stack temps aren't getting high enough, but I don't know why.

Lets review the case so far - Mike, correct any errors, and answer any assumptions please. I will edit this post with any extra details that you see need changing as to the facts of the install and what you have experienced

Differential Diagnosis (picture Dr House, at the white board, as we all sit around and name off ideas, except we won't shoot them down so quickly as he does on the show)
(I have reviewed Stihl Burning's posts to summarize what I will write here)

Patient is a 2004 Jotul Kennebec C450, installed with 22 feet of liner (assumed 6 inch), uses a Ventinox offset adapter to get thru the damper plate - basement install. No outside air kit. Assumed recent install (Oct 2008). Unit replaced a larger Elmira that performed well.

What we don't know - did you change anything else in the house since you replaced the Elmira with the Kennebec? Windows, air sealing, new bath fan? We need to remove any other factors before we can assume that all that is changed is the stove. At one poinmt yopu mentioned an upstairs fireplace as well - what is in that hearth?

Symptoms - poor burn at initial install, complaint of blackening glass quickly and no heat, and then Stihl found the bad gasket. Complaint of Low heat output - noticable lack of increase in temp of the flue bricks inside the garage when compared to old stove. Continued complaint of creosote on glass. Mentions temps of 700F, but still getting black glass (note - these seem mutually exclusive to me - should not get black glass if actually getting 700F)

First principles says - wet wood, poor/choked draft, blocked intake.

Wet Wood - I don't recall getting any moisture readings from your woodpile, or even asking about dry wood - make sure we have that covered off. Could even buy a bag of gas station wood if you have any doubt (cheaper than giving up the cause). Try a load of 2x4s if we need to. Canadian Tire even has a moisture meter on sale this week. Evey man love a reason to buy a new tool.

Choked Draft - Flue cap plugged or creosote buildup are the usual suspects. Then comes mechanical depressurisation and stack effect. Do you get any smoke spillage on reload, or do you get a bright yellow flame? With the lack of heat symptom, it is possible that creosote has built up as a result of what ever is causing poor temp output from the stove. Stihl mentioned flue was clean in Oct, but is it still clean now? - it can plug up quick if the perfect storms of bad factors line up. JIE asked in a post on 18 November if the offset adapter could be causing a draft prblem, but we havent gotten an answer on that question yet. Basement install also make this a candidate for a negative pressure issue - do you get any improvement if you crack a window? See more under intake...

Intake - I think you have fixed the physical intake issue (gasket and ashes plugging the inlet), assuming that nothing is plugging the inlet port at the rear of the stove where an OAK would connect (this you should have checked already, but I don't want to leave out even the obvious stuff). Being a basement install, the lack of an OAK could be limiting intake ability, again, try opening the window - we are diagnosing here, so, yes the room will cool, but if you have a pressure problem, the open window will let the stove breathe.

Mike, do you see any errors or ommisions? I would love to get you a well working stove for Christmas.

Brent: Wow you certainly did your homework! The house is the same as last year except for an exhaust fan that was installed in the upstairs bathroom. The upstair's hearth has the old Sear's bay window glass doors and a chimney top damper. The chimney isn't safely accessible now, but the draft is strong with the door opened but spillage will start within about five seconds after it is opened too wide. (Elmira was the same) Since following your suggestions, I'm running the intake air opened more, and longer, dirty glass is not really an issue. (ie: last night I turned it down to about 5/8 and fell asleep, and the glass was perfectly clean in the morning). Also one other observation, I burned the pieces of a mandrin wood crate, in well established fire and the secondary combustion really lit off with a rolling flame, so fundamentally it seems good. I just came back from my friend who lives a little north of me with a new PE stove, replace an Elmira stove as well. His is rated at 97000 btu. I guess the biggest difference, what I am probably missing is the size and mass. None the less I believe all of you who are telling me I should be feeling more heat. Also I routed my outside air, up over the top, and to the front of the insert. I guess if I could resolve this mystery, it would be as good a Christmas gift as any.

Thank You all for your concern and suggestions (especially you Brent)
Merry Christmas and Happy New Year!

Stihl, Sounds like you are making some progress. It sounds like we have an almost identical installation, basement fireplace with the one above on a exterior wall. I am going to pick up our IR gun from work while I am off and get some temperatures, the surround , the stove, and the masonry wall sides and above the stove. When I have had it up to temperature for a while the brick on both sides of the surround really put out some heat as well as the brick part way up to the mantle. Don't give up yet. Merry Christmas and Happy New Year, Jim

Stihl Burning said:

Brent: Wow you certainly did your homework! The house is the same as last year except for an exhaust fan that was installed in the upstairs bathroom. The upstair's hearth has the old Sear's bay window glass doors and a chimney top damper. The chimney isn't safely accessible now, but the draft is strong with the door opened but spillage will start within about five seconds after it is opened too wide. (Elmira was the same) Since following your suggestions, I'm running the intake air opened more, and longer, dirty glass is not really an issue. (ie: last night I turned it down to about 5/8 and fell asleep, and the glass was perfectly clean in the morning). Also one other observation, I burned the pieces of a mandrin wood crate, in well established fire and the secondary combustion really lit off with a rolling flame, so fundamentally it seems good. I just came back from my friend who lives a little north of me with a new PE stove, replace an Elmira stove as well. His is rated at 97000 btu. I guess the biggest difference, what I am probably missing is the size and mass. None the less I believe all of you who are telling me I should be feeling more heat. Also I routed my outside air, up over the top, and to the front of the insert. I guess if I could resolve this mystery, it would be as good a Christmas gift as any.

Thank You all for your concern and suggestions (especially you Brent)
Merry Christmas and Happy New Year!

Click to expand...

Guys: Yesterday was warm, actually almost double the previous record high16c vs 9.7c fo Dec 27th) so I managed to yank my insert and fab up a two piece block off plate, I also did find, in the process some unsealed bits of my liner connection that I sealed with stove cement about 1/4 perimeter. First of all I have to say sorry for being a "sceptic", but it was really more the house that improved more than the stove. I could NOT have been more wrong in ass-umming that the plate at the top of the liner could do all the work. Today we are back down to 2c about 35F and my living room hallway temp is 72.9F, and I didn't even run the furnace fan all day let alone the furnace. Furthermore the bedrooms above are way warmer! I guess I had the same draught (and thought it was normal) with the Elmira, but it could compensate! Also I have been running the stove with 2-3 pieces of wood and shut down 2/3 to 3/4. I'm glad it was worth the effort, as this was one hard to reach, sh-ty dirty, non ergonomic job that wouldn't want to do for even $100 an hour. No wonder many installers deem it an "unnecessary option". Brent Thank You again for your concern, and help and "never losing your cool" while coaching me through. P.S. the stove seems to be burning more complete, leaving less coals. The heat retention of the house is night and day! I tried to post pics,but they are too large, and I'm not that computer savy.

Stihl, Awesome news Glad to hear that the weather was cooperative. It is truely a dirty job but well worth it. Happy(warm) New Year, Jim

I've been following this thread with some interest -- I had a Jotul 550 installed about 2 months ago. My installer also didn't seemed concerned about installing a block-off plate. While I haven't had the problems Stihl has, I just think I could improve things with a a block-off plate. Stihl, would you mind giving a quick synopsis of the block-off plate installation? I know the wiki here has directions for a 1 piece block-off. How did you construct the 2 piece? Thanks.

I have been burning with the 550 for about 6 wks. Some lessons I think I have learned (thus far):

1) This stove works best when it is running all the time. It takes a little while to hit its groove from start up.
2.) I have found that getting the stove up to 700* (therm in blower vent) gradually choking down the air, and setting the fan speed lower seems to allow for better heat output.
3.) I have a fully lined chimney with block off. I think I will put some fireproof insulation around the liner at the damper and at the top of the chimney this spring.
4.) I have a lot to learn about loading the firebox for longer burns.
5.) I will learn many more lessons as the winter rolls on. But I have to say that I enjoy the hell out of taking a more active role in the heating of my home.

JJEGLBS: My install pretty much replicated the original damper at the top of my "heatalator" fireplace. I made two templates out of cardboard, and kept trimming and trial fitting the curve around the liner and matching the rest of the damper opening. I ended up with two pieces of stainless that had contour of the liner with "over lapping fingers" (kind of looks like the side view of a molar tooth. Each template probably involved 5 trial/trims. The sheet metal was probably 2-3 tries. You need to be able to work too at least + or - 1/4" and 1/8" would be better. My method may be the wrong approach for your fireplace, so you have to be a little creative. My block offs were all flat sheet metal. I did like how somebody on this site did a perimeter out of angled sheet metal and then filled and sealed the middle. Maybe if you can post a picture, you may get some suggestions. It was a "ball breaker" but in the end, very much worth it. Again, easy to understand why most installers shy away and don't reccomend a "block off" I for sure was skeptical, but now will have to become a "block off" Preacher. (Thank You, again Brent!) Like I said it was actually the house that became more tight, than the stove running better, but the stove is for sure leaving less and more finer coals. Cheers and Happy New Year to All!

Stihl - awesome!

Now I need one of those block offs installed (LOL - I'm still waiting for my installer to come and fix a liner issue first).

Don't thank me, I just pass on what was passed on to me, and rather adamantly too at times (Ask Rudyjr - I can be a dog on a bone, and not know when to let go).

Keep warm, burn safe.

Stihl Burning said:

JJEGLBS: My install pretty much replicated the original damper at the top of my "heatalator" fireplace. I made two templates out of cardboard, and kept trimming and trial fitting the curve around the liner and matching the rest of the damper opening. I ended up with two pieces of stainless that had contour of the liner with "over lapping fingers" (kind of looks like the side view of a molar tooth. Each template probably involved 5 trial/trims. The sheet metal was probably 2-3 tries. You need to be able to work too at least + or - 1/4" and 1/8" would be better. My method may be the wrong approach for your fireplace, so you have to be a little creative. My block offs were all flat sheet metal. I did like how somebody on this site did a perimeter out of angled sheet metal and then filled and sealed the middle. Maybe if you can post a picture, you may get some suggestions. It was a "ball breaker" but in the end, very much worth it. Again, easy to understand why most installers shy away and don't reccomend a "block off" I for sure was skeptical, but now will have to become a "block off" Preacher. (Thank You, again Brent!) Like I said it was actually the house that became more tight, than the stove running better, but the stove is for sure leaving less and more finer coals. Cheers and Happy New Year to All!

Click to expand...

Stihl --

Thanks for the detailed explanation. Did you have any problems disconnecting and reconnecting the flue? I won't have a lot of room to work with around the insert, so I assume I'm going to need to pull it all the way out?