Morso 1125 stove flue damper....open or close?

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Erich

Member
Hearth Supporter
Nov 8, 2008
28
Pennsylvania
I have a Morso 1125 stove that I recently got (obviously) used. I am having trouble with it running too hot. Now, I know that the handle on the right door controls the incoming air and controls the heat. But my question is: to run cooler, do you open or close the flue damper? I thought to run as cool as possible you closed the front door as tight as possible and closed the flue damper. But, I am wondering if that is backwards, and closing the flue damper is my cause for it running hot. Can some one tell me which is right? Does the closed flue choke the fire, or hold the heat inside?
 
Erich said:
I have a Morso 1125 stove that I recently got (obviously) used. I am having trouble with it running too hot. Now, I know that the handle on the right door controls the incoming air and controls the heat. But my question is: to run cooler, do you open or close the flue damper? I thought to run as cool as possible you closed the front door as tight as possible and closed the flue damper. But, I am wondering if that is backwards, and closing the flue damper is my cause for it running hot. Can some one tell me which is right? Does the closed flue choke the fire, or hold the heat inside?

To answer your question, great question by the way, about a flue damper my understanding of it is, that you close the damper as the stove comes up to temp to retain more heat in the firebox, and less in the flue.

When you mentioned you thought you closed the door as tight as possible did you mean the fresh air intake? If you did then yes you are correct you close the fresh air intake to slow the fire down there by reducing the amount of heat put out. If you also have a flue damper I would run that wide open to allow as much heat to go up the flue as possible.

But mainly my question is why? How do you know it is too, hot, are you gauging it with a flue temp gauge or a stove top gauge?

What is your chimney set up like? You could have an over draft situation where the draft is so strong that regardless of how much you neck it down, the upward draft created by the chimney is so great it is over compensating for the dampering down.

Also when you load your stove are you packing it right full? Or are you just putting enough wood in to create the amount of heat needed with out underfiring the stove.

Other factors could be stove too large for the area it is heating so even at its lowest setting it FEELS too hot in there regardless of what you are doing to cool it down.

again great question and the more info you can provide the better we can understand your situation, and best help to figure it out with you.
 
Question number 2: I built a ceramic tile wall over durock with the 1" air gap between it and the sheetrock. Tonight I am going to lower a tempurature probe down behind it to see how hot it gets back there. I'm sure it's ok because I built it to spec and kept the stove 14" away from it which is more than the required 12", but MAN!! that ceramic tile gets hot! I would guess it gets over 200 degrees. But, I know the important temp is the temp of the sheetrock. That is the job of the tile wall, to protect the combustable wall. But MAN!! it scares me being that hot. I guess my question is, is it normal for the ceramic tile to get that hot?
 
Thanks for replying vasten. When I say "overheating" I mean the room that the stove is in gets extremely hot, I'm sure the stove is within designed temps. My chimney setup is the flue comes off the top of the stove, goes 45 degrees to the wall thimble, then outside on the wall is a cleanout "T", then it goes straight up through the eaves 6 feet high, and at that point is is over 2 feet over the peak of the house. All triple wall stainless. I have been around a few stoves in my life, and I get the feeling this setup drafts extremely well. When I said I closed the door as tight as posible, that is how you control imcoming air on this model stove. There is no other incoming air damper on it, the handle tightness basically makes a controled leak between the 2 doors. The first few times I filled the stove I filled it right up, but after I realized how hot it was in the room, I started only feeding it one piece of wood at a time. That helped, but still pretty hot.
 
based on what you just stated I am going to assume the stove may just be too large for the area that you are trying to heat.

Are there any doors, to other rooms that you could open or could you cut in some vent to allow the heat out to other areas of the bldg?

Man if I had one complaint about a stove, safely overheating the area is the best one to have.
You know you will always be warm.
 
TIGHTEN THE NUT ON THE INSIDE OF THE DOOR HANDLE. That is my old stove. You can idle that baby down to a smolder and the stove will be just warm to the touch. You can get 12+ hours out of a burn. I could even get 24 hours of smoldering on warm days instead of having to relight it. I used that nut on the inside of the handle to allow more air in for the really hot burns. It allows more air in then the tapered cam on the handle. Bring the nut all the way in then play with it until you get it right.
And yes, you shut the damper when running, open it to rev it up or open the doors.
 
Thanks for the replies guys. I think I found another problem and fixed it. The rope seal in the doors was 1/4", and it didn't seem to even be touching. I changed it to a 3/8" rope, and when I first shut the door it poofed out the flame! Adjusted the latch and it is running pretty good now. I will keep playing with it, but I think after a week or so of trial and error I will get it. Lecomte38, thanks for the encouraging words, I like thougts of getting 12 hours out of it! I thought it was only good for 6 hours or so, but now I know it will go all day if I can figure it out! I'll let you all know if I make it through the night tonight, I just filled it on up! Oh, and my ceramic wall is cooler now, and behind it it is hangin between 105 and 125 degrees, well within fire danger range.
 
OK, here's an update. Last night I filled her right up at 8 pm, and this morning at 5 am it was still burning and still had a well established log, I think it will go another 3 hours or so. I'm letting it go out though, it's supposed to hit 55 today!!!! Anyway, thanks for all the help, it looks like we finally got it running as it should. It's nice to sit at home with it 40 degrees outside and be comfortable in the stove room and not wake up every 3 hours to add 3 more logs!
 
A couple things I did to my old 1125 to make it more user friendly:
1. installed a piece of sheet metal across the inside of the short front grate to stop ashes from falling out the door or blocking the air intake.
2. drilled a "start hole" in the side with a slide shut off door. I'd drag a single hot coal out of the ash and put it in front of this hole with 2 split logs over it. By the time I could make coffee I had a raging fire and was ready to load for the day. NOTE: For a few years I only started 1 fire per year and kept it going thru the whole winter with that stove loading it twice per day.
3. For MAX HEAT you can stand the wood up on end and pack 1/4 cord in the beast. Do not try this unless it is way below 0 outside.
 
GREAT idea on the metal across the front grate, I have been running this stove less than a week and I am already sick of the ash falling out onto my hearth whenever I open the door. Thanks for the idea! I was also thinking of extending that grate a little higher because I had a log roll forward onto the doors. Guess what happened when I opened the door after that?! Good idea on the hole too, I have noticed that I need to leave the door unlatched until I have a good bed of coals going or I will snuff it out. I think I am going to wait on that though, I am a little gun-shy to drilling any holes in it yet! Thanks for all the help. Again, sheet metal behind the grate, great idea.
 
lecomte38 said:
TIGHTEN THE NUT ON THE INSIDE OF THE DOOR HANDLE. That is my old stove. You can idle that baby down to a smolder and the stove will be just warm to the touch. You can get 12+ hours out of a burn. I could even get 24 hours of smoldering on warm days instead of having to relight it. I used that nut on the inside of the handle to allow more air in for the really hot burns. It allows more air in then the tapered cam on the handle. Bring the nut all the way in then play with it until you get it right.
And yes, you shut the damper when running, open it to rev it up or open the doors.

I'm running a Morso 1125 and am curious about your experiences.

1) What were your stove/flue temps like when running a long / overnight burn?
2) How far did you close the damper for a long / overnight burn: half, 3/4, or more?
3) What kind of creosote buildup did you encounter running the stove this way -- how often did you clean your chimney?
4) How big a space were you heating with the stove?

Thanks.
 
I have one more question for the 1125 fella's here. What thickness rope seal goes in the doors? I used 3/8" and it seemed too thick, but 1/4" seems too thin.
 
Erich said:
I have one more question for the 1125 fella's here. What thickness rope seal goes in the doors? I used 3/8" and it seemed too thick, but 1/4" seems too thin.

3/8s works fine -- it will compress a bit and conform to the door seal.
 
Answers to questions above:
1 stove/flue temp - between 125 and 700 - with the stove shut all the way down the whole stove and stack were just warm to the touch
2 close damper all the way
3 made as much creosote as I could. A good roaring chimney fire will burn that out. ( obviously try to burn dry wood )
Clean the chimney once a year - 8" flue pretty plugged by then.
4 I was heating a 1400 sq foot ranch in Massachusetts.

I never had to replace the door rope.
 
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