Starting my second season with an Oslo .I have a 26 foot exterior chimney . Using hardwood aged two and a half years this thing just eats wood. Lights really easy.I tried putting a baffle in my stovepipe and it only helps a little. It gets hot when wide open but the temp drops when i cut the air past halfway. Only get 3 to 4 hours out of a load. Disappointed in the lack of overnight burn.
Oslo short burntimes
- Thread starter Bruce P
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xman23
Minister of Fire
It's hard to say what's normal. All depends what and how you need to burn. If I have a bed of coals, a singe split or two will burn for a couple of hours with a choked down air supply. The stove heat cycles up and down only 250 degrees. If it's not below 30 outside that's about all the heat I need. For overnight I get the box stuffed with oak, get it hot and choke it down. Based on the need for heat, reload when ever there is room. This produces a deep bed of coals, but get me the longest heat time.
Pellet_Pete
Feeling the Heat
I get 3-4 hours of top-end heat from my little Jotul F3 burning hardwood @15%MC with a 17' chimney. If I reload at 10:00 or so with good wood, I will almost always have a warmish stove with coals at 6:00 for a reasonably quick relight. In other words, I'd expect the Oslo to handily beat that, so something is certainly amiss.
Do you mean the baffle here, or the primary air intake? If your primary needs to be open >halfway to stay hot, then I'd say there's an issue with the wood. I don't have any personal experience with baffles, but I'm assuming closing that more than halfway is generally an extreme measure. Did you install the baffle after some runaway burns or overfiring, or were you just trying to slow down the wide-open stove burn?
Woody Stover
Minister of Fire
Sounds like you can leave the pipe damper all the way closed except on startup or when reloading. How thick are your splits. They should be in the 5-8" range.
firefighterjake
Minister of Fire
Out of curiosity ... with the chimney damper wide open how is the stove's air control? Assuming you have a stove top thermo and.or flue thermo ... once it's up to temp and you slide the air control shut what occurs with the fire, heat and time of burn.
Yes , wood is aged exposed to sun and wind all summer ,covered in the winter, top covered last year ,left uncovered this summer due to lack of rain
It slows down the flames and the temp drops but still burns down quickly to ashes, fully loaded 4 hours max
CentralVAWoodHeat
Minister of Fire
Yup. It's a Jotul. That's about what you will get. As I've said before on other threads, with dry wood, you'll get excellent heat and top notch efficiency but don't expect anywhere close to an overnight burn even with a medium or large Jotul. They are meant to burn hot and efficient.
Ashful
Minister of Fire
This does not agree with the experience of the majority of Jotul owners on this forum. Yes, they have burn times much shorter than a good catalytic stove, but they are not typically claimed to be any worse than any other non-cat.
Since it sounds like your air control is working, let's assume it's not a leaky gasket issue. It sounds to me like this stove is just undersized for the heat demand. What's the square footage and construction?
CentralVAWoodHeat
Minister of Fire
Don't get me wrong, I get the full '8 hour burn' the Castine reports. However, like we all know, the definition of this varies. I can restart the stove with remaining coals after 8 hours but that means it has hovered at under 250 for many hours, making it not really a heater for the latter half of the burn.
You are correct about sizing, Ashful. I heat a 2200 square foot home with a stove meant for 1700 square feet and consider upgrading the size often. The trade off then though is cooking yourself out of the main room where the stove is located.
I really like my Jotul but if Bruce P is getting 3-4 hours of fire and very hot coals per load, his experience is in line with my own.
2fireplacesinSC
Burning Hunk
I get more than that out of my much smaller F3 (~1.1cu feet I think, compared with ~2.8cu feet for the F500) with hard woods. With soft woods, I can get 5 hours of heat often if loaded up to the max and I have a 28 foot chimney (interior though). Now if you're talking big flames, I can get 1.5-2hours out of soft wood, but it'll be rocking away at 350-400 degrees 3 hours in even with soft wood.
Jotul does also say in the manual that if your wood is TOO seasoned, you won't get significant efficiency improvement through using the stove. Although I don't think anyone but Poindexter has ever had that problem in reading the forums
. Therefore I REALLY doubt that's the issue. Here is the money quote:
page 14 of the F3CB manual
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The F 3 CB is designed to burn natural wood only. Higher efficiencies and lower emissions generally result when burning air-dried, seasoned hardwoods, as opposed to softwoods, green or freshly cut hardwoods. Wood that has been air-dried for a period of 6 to 14 months will provide the cleanest, most efficient heat. Wood seasoned more than 2 years will burn too quickly to take advantage of the stove’s low end efficiency strength.
=============================
Some questions that come to mind as I read through this:
What's the wood moisture content? (freshly split, middle of the piece)
Any block off plate or insulation? (you said it's an exterior chimney.)
What temps are you getting? (wherever you're supposed to measure it by the manual)
Dollar bill test negative?
Woody Stover
Minister of Fire
Good catch. The OP hasn't mentioned yet if he's done the dollar-bill test on the door and ash pan gaskets, and these need to be checked before looking elsewhere.
claydogg84
Minister of Fire
Burn times are very misleading. My Oslo gets a solid 4 hours, maybe 5, of usable heat. It's generally in the coaling stage about 3 - 3.5 hour mark. All secondary combustion stoves will fall in line with these numbers with the major variance being the size of the stove itself. I routinely load in the morning after about 9 hours with just a couple splits and the door cracked.
New Construction,well insulated open floor plan 1000 feet downstaires 700 feet upstairs 9 foot ceilings downstairs
But its been burning like this fron day one unless it came with a leaky gasket on the side door new ?
Woody Stover
Minister of Fire
Did it pull out easily or was there still a fair amount of resistance? I would imagine it has happened before that a stove left the plant with a faulty gasket install or some other problem that caused an air control issue. What about the ash pan gasket, did you check that as well? I'd think you'd be able to tell by looking at the coals weather the box is getting air from underneath.
If the gaskets have checked out, AND the bolts for the ash pan are tight, and there are no leaks in the cast plates all around, try this-----
Oslo's air control is kinda crude, not exactly a fine tuned mechanical device.
if your draft is excellent or too strong:
try shoving various 'grits' of steel wool in the primary air entrance in the center rear base of the Oslo. Experiment with the
amount and category (grit) of steel wool ( 0 to 000 )until you get some lessening of air and longer burns.
And, mixing some big chunks for an overnight burn.
YMMV
Oslo's air control is kinda crude, not exactly a fine tuned mechanical device.
if your draft is excellent or too strong:
try shoving various 'grits' of steel wool in the primary air entrance in the center rear base of the Oslo. Experiment with the
amount and category (grit) of steel wool ( 0 to 000 )until you get some lessening of air and longer burns.
And, mixing some big chunks for an overnight burn.
YMMV
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