Advice for improving draft in our new Jotul Oslo F-500

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RobOnBusiness

New Member
Nov 24, 2020
2
Perth, ON, Canada
Hello master wood burners,

I just installed our new Jotul Oslo F-500 in our 27' Yurt here in Wisconsin. I completed the 3 break-in fires this weekend, per manufacturer guidelines, and the stove kept us warm all night despite outside temps in the 20s.

I am noticing an issue however regarding adequate draft (or perhaps intake) for this otherwise awesome stove. I am unable to maintain a secondary burn, even with the primary air intake open all the way to the right for maximum intake. If I leave it in this position, the fire gradually dies down and smoke begins to rise out the chimney pipe. If I crack the ash pan door, then of course the fire starts ripping again and I can see the secondary burn in action, and no more smoke out the chimney. The Manual says to never operate the stove with ash pan door open due to risk of overfilling, so I nervously kept a close eye on my stove temp and the fire all night, but I couldn't get the stove to burn properly with it sealed all the way up and only using the primary air intake valve.

I'm not sure if the issue is my chimney height or if there is some other troubleshooting I need to do with the intake?

I first figured I would address the chimney issue. Per the manual for the F-500, it recommends a minimum of a 15-ft chimney for adequate draft.

I am using a 6" double lumin galvalume class A exterior chimney. I used DVL (double lumin) stove pipe from the stove to the chimney-the stove pipe rises about 32" from the top of the stove to a right angle, and then attaches to the galvalume (via thimble) and out the wall. The chimney height from this point was just under 12 feet to start. After noticing this draft issue, I added another 36' section of pipe. The total exterior chimney hight is now around 14.5 feet. (If i add chimney+ stove pipe height =17'ft, ie total run from top of stove to top of chimney). I lit another fire and didn't notice much difference. (see pics) Hmmm.

I'm wondering if I need to continue adding height to my chimney, or if there is some other strategy? I guess cracking the ash pan door is not the biggest deal in the world, but I don't like disregarding the manual instructions on this. I called the Jotul North America technical office and left a VM, awaiting a call back.

Any ideas or input much appreciated,
Did you ever hear back from Technical support? I have the exact same problem... My dad set up his Jotul front loading stove in his newly built modular home back around 1998-2000, so it's been operating each winter since then. Except for the last one. He passed away in Feb./19, and I decided to retire and live in his home, arriving July this year. However, I can't remember any time my dad could use only the front draft control over the time he ran it - we always had to keep the ash door ajar to varying degrees, to keep the fire lit. It's been a great stove except for that. It runs a horizontal pipe about 3' straight out the back stub and then runs straight up the doublewalled chimney pipe about 30'. Like yours, it rips when on primary burn with the ash door opened against the front of the latch catch. after coals form, I can run on secondary burn and modulate it behind the latch catch. I realize I may have slightly moist wood - red oak cut and split coarse a year ago. I disconnected the draft tube from the stove back and ran it open to see if there might have been a restriction in the outside feed pipe or screen, but little difference. After having sat and watched and fed the fire for about 2 months now, I'm having ideas about how I might like to modify it so it doesn't matter so much about the dryness of the wood or the load in the firebox. There are a few neat examples of a thermostatically governed inlet door, and I could shorten the internal air passages some to help the flow. I'm a heavy duty mechanic, so understand a few things about fire in the hole, if you know what I mean. I am mindful of the cracking possible in the bottom frame. Just thought I'd ask what your take on your experience shaped up to be.