Jotul F3 over fire problems

[wormy]

Hey, I have a new jotul f3 and simply love the stove. Burns great and heats wonderfully.
I have only one problem. It seems that if I add more than one piece of dry red oak or loqust the stove quickly goes to 700 degrees or hotter with no control. Of course I completly shut off the air before loading. Im vented vertically out the back of the stove with a tee about 14 feet high with Dura vent pipe. Wondering if I should consider a damper. Right now burn times are short because I can only load one piece at a time to prevent over fire. Any one else had any experience????

 

[begreen]

I had a similar setup and had to add a draft damper on our F3 to gain a better degree of control over hot fires. It will settle down, albeit slowly if the air is restricted, but if done too quickly it can backfire when the unburned gases try to ignite. The draft damper made a lot of difference in the degree of control. We could keep the air control open much wider with a fresh load of wood and the stove seemed to heat better too.

Before opening the door to load wood, one should open the air control (and draft damper if installed) first.

 

[Roospike]

Boy that just dont sound right at all. Sounds more a like the workings of a pot belly stove with that lack of control.
"1 log , air turned all the way down and a fire running up to 700°" !?!?!?

Vented out the back with a T and only a 14' high stack sounds more like it should have under draft issues and not run away fires.

Stove sounds like its not air tight or a bad seal system.

 

[Roospike]

Do a search on the fourm on your stove ........hear is some reading of the stove that you might find interisting .

#1 https://www.hearth.com/econtent/index.php/forums/viewthread/1237/P0/

#2 https://www.hearth.com/econtent/index.php/forums/viewthread/46/

 

[MountainStoveGuy]

Make shure the ash pan is shut tight, and the door seals are all in order. Do the dollar bill test.

 

[BrotherBart]

Make shure the ash pan is shut tight, and the door seals are all in order. Do the dollar bill test.

Yeah, I am thinking ash pan area air leak here too. The ash pan housing on the F3 is sheet metal and there is a thin ceramic glass gasket between it and the stove bottom. If the screws are loose that pup would be sucking major air up through the grate.

Also, I have to ask the OP if he is closing the center "start-up" air inlet in the middle of the door by pushing it to the left after the fire starts up. I forget the thing all of the time.

 

[webbie]

That stove has a small firebox - and a hot one. It will tend to go up and up. Yes, I think a damper might help - or maybe have some wood that is not bone dry. Since it is a "base burner", meaning most of the base of the fire is always sitting on hot coals, it can be tough to turn it down. When you add new wood, that starts the burning of gases at the top of the stove (it's a non-cat), which of course raises the temp.

You might be able to experiment moving the hot coals to one side of the firebox before reloading - or maybe to the rear, so you lower the amount of critical mass burning at once.

 

[wahoowad]

Maybe it is your thermometer? I had to buy three and do some calibration testing before I finally had one I felt was close. Now I have two I trust although there are even differences between these. Both provide the same temp at a stable burn but one seems to take longer than the other to respond.