Jotul F3CB smokes from the rear on start up

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MuskieC

Member
Jan 3, 2014
8
North Carolina
We have a Jotul F3CB that we have been using for about 8 years. Love it! Last couple of years have experienced smoke coming from the rear of the stove when first firing it up. This is even with the front door open , fire burning well and the chimney drawing well. It only lasts during the initial fire up phase, but it never used to do this. Chimney is newly cleaned, stove operates well. It is vented straight up from top of stove. Is there a spring controlled air valve on the back that could be stuck?
 
We have a Jotul F3CB that we have been using for about 8 years. Love it! Last couple of years have experienced smoke coming from the rear of the stove when first firing it up. This is even with the front door open , fire burning well and the chimney drawing well. It only lasts during the initial fire up phase, but it never used to do this. Chimney is newly cleaned, stove operates well. It is vented straight up from top of stove. Is there a spring controlled air valve on the back that could be stuck?
Try preheating the flue with a heat gun 10 minutes or lighting a fire with kindling first and see if it still does it.
 
Try preheating the flue with a heat gun 10 minutes or lighting a fire with kindling first and see if it still does it.
I start with a small, hot kindling fire and gradually add to it. Chimney is drawing fine, but smoke still issues from the rear air intake. Doesn't make sense to me.
 
Is the stove top or rear vented? Was the stovetop removed for cleaning in the past couple years?
 
I start with a small, hot kindling fire and gradually add to it. Chimney is drawing fine, but smoke still issues from the rear air intake. Doesn't make sense to me.
Is the door open or closed what the smoke comes from the rear? Some stoves require the door closed. I had a similar issue once with jotul blackbear CB and thought it was a stove leak but I never found it... But it went away when I closed the door and preheated the flue with a heat gun in the stove. Only smoked upon start up at the rear..
 
Is the door open or closed what the smoke comes from the rear? Some stoves require the door closed. I had a similar issue once with jotul blackbear CB and thought it was a stove leak but I never found it... But it went away when I closed the door and preheated the flue with a heat gun in the stove. Only smoked upon start up at the rear..
I usually start with the door open to get good draw. I have tried closing the door when it starts smoking from rear but that just causes it to smoke more. It only takes it a couple of minutes to get going and for the smoking to stop, but it is something that did not happen the first few years.
 
Try lighting fire with door closed (preheat flue with heat gun) after lighting and see if smoke comes out rear. Then try with just lots of dry kindlin and no wood. This stove has an ashpan, a start up air control and primary air control correct? If so, check the ashpan door gasket by removing pan and placing flashlight inside and closing the door. look for light at the edges. The manual suggests 2 ways of lighting. Need to find the problem with process of elimination. Sometimes it can be a wood issue.
 
It is top vented. I clean off the top shelf in the stove every year.
So the top has not been removed? Where in the rear exactly is the smoke coming from? Can you post a picture of that location?
 
So the top has not been removed? Where in the rear exactly is the smoke coming from? Can you post a picture of that location?
I comes out from behind the heat sheild on the rear of the stove, Behind the sheild is a secondary air intake that feeds the air distributor over the fire box. Just not sure just what would cause smoke to be forced back through the distributor and down to the intake when the chimney is drawing hot air up.
 
I comes out from behind the heat sheild on the rear of the stove, Behind the sheild is a secondary air intake that feeds the air distributor over the fire box. Just not sure just what would cause smoke to be forced back through the distributor and down to the intake when the chimney is drawing hot air up.
A backpuff will do that, but as described, this sounds different. Pull the rear heat shield and examine the back for cracks or a leak at the rear vent knockout.
 
you sure the top of the stove is seated properly and the rope gasket in good shape? I sometimes had mine look like it was on correctly but not fully seated in the groove.
 
you sure the top of the stove is seated properly and the rope gasket in good shape? I sometimes had mine look like it was on correctly but not fully seated in the groove.
Yes, that's why I asked if the top had been removed. Got a negative on that.
 
Is the door open or closed what the smoke comes from the rear? Some stoves require the door closed. I had a similar issue once with jotul blackbear CB and thought it was a stove leak but I never found it... But it went away when I closed the door and preheated the flue with a heat gun in the stove. Only smoked upon start up at the rear..
It appears you are correct! I assumed that starting a fire with the door open would assure a good initial draft up chimney. But if I start the kindling then close the door with the door draft vent open I get no smoke out the back. Not sure I understand it, but it works! Thanks.
 
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Try Top Down Starting. With the flames immediately hitting the top baffle, the stove establishes draft much faster and cleaner so it's a double benefit. Faster Heat up, and less smoke produced to leak into your room.
I've posted this on a few threads but here is how i do it in my jotul if you have not seen it.


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It appears you are correct! I assumed that starting a fire with the door open would assure a good initial draft up chimney. But if I start the kindling then close the door with the door draft vent open I get no smoke out the back. Not sure I understand it, but it works! Thanks.
Thanks...I also believe the secondary air is responsible or contributes in pushing air out the stove when reloading sometimes...

Get your self a small heater and pre heat....for 10 or 15 minutes...i put my small heater up against the stove with a foam pad to eliminate ash blow back...