Jotul Oslo Hard To Start

[Threelittlefish]

My first week with this stove and one thing I noticed is this thing is a groan to get going. Ambient temp 40F. 30’ straight run double wall stove pipe. Great draft. Put 1/2 a Super Cedar in a good amount of kindling and 2 splits. Primary air wide open. The Super Cedar gets things going well. No complaints there. Once the SC is burned out flames are slow and sluggish. Flames are off color not bright yellow and starved for oxygen. The fire is not getting enough air.

Primary air inlet design is poor. Crack the front door 1/2 an inch and things get going again. Close it again and the fire dies down. Wood is dry sugar maple aged 1.5 yrs. For the hour or so it takes to get some coals this stove is worthless. Who has an hour to get a stove going?

Has anyone confirmed it’s the primary that’s the problem? Any fixes? It’s a beast once it’s up and running but this stove requires patience when starting cold. I took off the primary air cover and confirmed everything was operating normally and it is. Primary air lever is free and has full range of motion. I also noticed if you go to reload the stove and put a fresh split in east - west in front of the primary your asking for problems.

This stove replaces an EFEL S33 which was quick to light off and get everything burning. Minimal hassle.

If it helps this stove is an old F500 version 1.0.

 

[Geoff C]

Ever try top down start?

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[jotulguy]

It’s important to remember two things, the stove doesn’t supply draft the chimney does and your old stove was less efficient and gave more heat to the chimney. More heat = more draft. 30’ of chimney will take some serious heat to get the draft started. If possible use smaller pieces and plenty of them to help push through and start your draft.

 

[Woody Stover]

Wood is dry sugar maple aged 1.5 yrs....This stove replaces an EFEL S33 which was quick to light off and get everything burning.

How was this wood dried? Split and stacked in the wind and top-covered for 1.5 years? Is the fuel you are using now identical to what you burned in the Efel?

 

[logger]

I owned an Oslo for years and never had trouble starting it up if the wood was under seasoned. Why are people so quick to blame the stove before they consider their stack/draft, wood, or other possibilities? Not necessarily directed at you but people complain about the stove instead of what the problem really is. I’d look into those things first. I have friends and family w Oslo’s as well, they are reputable and top notch cast stoves. I know they have some play in the intake lever, but that shouldn’t be a problem whatsoever. If the kindling and splits aren’t taking off it’s a draft issue or unseasoned wood. I’d try a bag of store bought wood to see if it makes a difference. Maple seasons quickly but depending on how and where it’s stacked it’s possible it’s still under seasoned. Do you use a moisture meter on the splits? That might give you a better idea of how far along the wood is. I’ve seen it a million times on this forum where people think the wood is perfect when in fact it turns out to be the culprit. Oslo’s are very picky when it comes to seasoned wood.

 

[Sawset]

Crack the front door 1/2 an inch and things get going again. Close it again and the fire dies down.

I would say your wood is high moisture. Classic example.
Close the door on dry splits, flue temps should hold steady or rise.
Close the door on wet wood and the fire dies.
The damper is finely tuned to regulate the burn, but is not enough to compensate for the air needed to keep a wet fire going.

Crack the door open, damper open, start it and allow flue temp to go to 5-600
Close the door, flue temp fluctuates some, heads back up to 5-600
start closing the damper
Startup here is about 15-20min
With wet wood, you can fiddle with it all till the fire burns off all the moisture, could be for most of the burn cycle.
I fought it the first year. After that, dry wood is a wonderful thing.

For the hour or so it takes to get some coals this stove is worthless.

Your getting 20 lashings with a wet possum.

 

[Ctwoodtick]

If you don’t have a moisture meter- get one. (14 bucks from harbor freight) split a few pieces of your wood, test in that fresh split wood. If over say 24 percent or so, your wood is too wet and will be sluggish. The wood will be best 20 % or lower but IMO under 23 should get you where you need to go.

 

[begreen]

The Oslo is not a hard to start stove. The most likely culprit is the wood.

 

[Threelittlefish]

I started this thread with all the pertinent info. It’s not the wood. I cut a split in half and tested it. 12%. I did a search and found there are others with this issue. I want to know if anyone has tried to modify the primary to fix the issue.

 

[Ctwoodtick]

I started this thread with all the pertinent info. It’s not the wood. I cut a split in half and tested it. 12%. I did a search and found there are others with this issue. I want to know if anyone has tried to modify the primary to fix the issue.

We only ask about the wood to be of help to you. A lot of guys say they have “dry wood” but that’s often not the case. Us double checking about the wood is to save you time and energy messing with a potentially unneeded modification. You’re a new member. Keep in mind you more apt to be helped if you politely say “thanks guys, but I’ve already checked the wood with moisture meter”. It’s free help after all.

 

[begreen]

Hopefully the wood is dry, but a 12% reading is suspect. That is very hard to achieve especially with a humid summer. Make sure the meter is working properly.

When moving the air control lever, can you feel the slider valve moving or is it super sloppy and loose?

 

[molly1414]

I have an Oslo with 20ft of pipe and it's very easy to start. A few pieces of pine and two fire starter sticks open the air and off she goes. I just started the stove tonight and it took 5 min. Your asking if anyone has modified the air to fix "the problem" and we are saying no because there is no problem. Have you looked under the stove in the back where the other air intake is to see if anything is blocking the air?

 

[begreen]

As noted above, I would verify the wood is not an issue by starting and burning a fire of dry construction cutoffs. (2x4s and 2x6 ends). And I would verify that the air control is working properly by pulling the doghouse cover and making sure that the air control lever is properly in the slot and that it works the air slider valve correctly.

 

[Threelittlefish]

Let me describe the situation in more detail. I don’t consider the stove running until it reaches what I would describe as the flashover point. The point where the wood ignites even when not in contact with flame. The wood is offgasing and that gas is combusting. The temp in the firebox is high enough that all the wood is being consumed.

Jotul recommends leaving the front door open while starting. Seems strange to me! My EFEL stove provided adequate air for a quick startup with the door closed. The EFEL has a pretty elaborate air handling system. It reached flashover pretty quickly. Approx 1/2 hr. If I kept the front door closed on the Jotul it takes about an hour.

The stove is 100%. I removed the primary air inlet cover and confirmed proper operation. The moisture meter is accurate. I live in the mountains and high humidity is rare. The wood is in a covered shed out of the elements but plenty of air movement. The wood is dry.

if the stove drafted properly on startup Jotul wouldn’t make the recommendation to open the door.

 

[Woody Stover]

Jotul recommends leaving the front door open while starting. Seems strange to me! ...if the stove drafted properly on startup Jotul wouldn’t make the recommendation to open the door.

I've read here that certain Jotul models like a little extra draft, so I wouldn't be surprised that having the door open would help in cases of marginal draft.
I think that most people that run the Oslo don't have any problem starting the stove, provided they have adequate stack height and draft. You have 30' straight up. If I were you I would focus on the fact that this is a used stove, and may have some issue that you haven't discovered yet, instead of trying to blame the design of the stove.

 

[XmasTreefarmer]

Well I hate to see a fellow Oslo owner having problems with their stove. There has been a lot of back and forth here - let me see if I can condense it down.

Draft - Fine (30' double wall insulated, straight up - man, I'm surprised it doesn't suck you in when you are lighting it!)
Wood - Fine (12% - wow! Here in Wisconsin around 17% is my Holy Grail)
Burns fine with the door open - That fits with the first two items - you have plenty of draft and your wood is better than good.

It sure seems like something is blocked in the stove air system. Here's what I'd do if I were in your situation:
The air intake for the stove is on the bottom towards the back of the stove. It's about a tennis ball size opening. That feeds both the primary and secondary air. Sooooooo, sure sounds like something is blocking the path from that air intake and the dog house.

I think I'd remove the doghouse, move the slider mostly closed, and blow some air in there using a compressor and air gun attachment. You could also try running something like a coat hanger from the primary opening back into the stove.

I'm probably going on and on here, but could someone have pushed something like a foil ball into the main air intake? Maybe it's shoved way up in there so that it's not visible unless you peer up in there?!

In looking at all that you have done and tried - a blocked passage is really all that is left.

When I think about how a stove could get messed up - it reminds me of something I saw on YouTube - the video was something about cleaning your stove or cleaning your glass ... well, the guy starts by showing shoveling out the ash in his stove and it is almost 1/2 way up the glass in front! OMG! Now something like that could clog up the primary air by sifting back into the doghouse and filling up the area below the slider!

 

[Woody Stover]

In looking at all that you have done and tried - a blocked passage is really all that is left.

Yeah, I was thinking maybe a mouse nest..

 

[XmasTreefarmer]

Yeah, I was thinking maybe a mouse nest..

Oh yes, hadn't even thought that it could have been stored outside in a barn or shed. Those little suckers will move right in. I could see them coming in right through the main air intake on the bottom, just hauling in nesting material.

 

[firefighterjake]

Maybe I'm doing it wrong . . . but I think what you've described ThreeLittleFish is normal . . . at least for me.

I find that the Oslo is a great heater that will pump out some serious heat reliably . . . but it is like a locomotive as it takes awhile to come up to speed and put out the heat. Honestly, an hour or so to get secondary burning is a bit long, but if I am starting a fire from a cold start I figure on at least half an hour to 3/4 of an hour to get things going nicely. Reloads are much, much easier . . .

So here's what I do . . . at least this is what works for me . . . your mileage may vary.

From a cold start . . .

I start with a top down fire. It helps establish a draft quickly and means I don't have to mess with reloading wood.

I then light the newspaper, super cedar, cardboard, etc. with the air control open all the way and the side door slightly ajar.

If the wood and kindling are in decent shape in terms of moisture . . . and with my wood at 2-4 years old it usually is . . . things get cooking pretty quickly. However, I like to keep the door ajar until my probe thermometer (double wall stove pipe) reaches 400 degrees or so . . . and then I close the side door, but leave the air control open.

Once the stove reaches 500-600 degrees on the probe thermometer I start to cut back the air . . . and witness the magic.

If my wood is less than optimal . . . i.e. I have some chunks that I have been seasoning outside for the last year or so . . . I find that the fire takes longer to get up to burning temps. It will get there eventually, but it is notably different from when I use the longer seasoned wood from my wood shed.

Good luck.

 

[Sawset]

Let me describe the situation in more detail.
Jotul recommends leaving the front door open while starting. Seems strange to me!
The stove is 100%
The moisture meter is accurate.
The wood is dry.
if the stove drafted properly on startup Jotul wouldn’t make the recommendation to open the door.

Get used to cracking the side door open on startup. It's effective, easy, and shouldn't really be an issue. Or you could get a third stove, and get to know the nuances it has, and then say, but the Oslo worked great just by cracking open the side door, now I need to do this wizardy, on to the 4th. I'm being a wise arse, but, it wants to work hard and put out some serious heat, you just need to figure in some get acquainted time.

 

[begreen]

Yeah, all stoves have their particular characteristics. The Efel S33 is a very nice stove, but quite a different design, firebox shape and air distribution. It's not uncommon to crack the door open until the fire starts burning well. I do this on the T6, especially with milder weather startups. When it's 25º outside this may not be necessary, but at that point I am burning 24/7 so it's a warm startup.

 

[semipro]

Get used to cracking the side door open on startup. It's effective, easy, and shouldn't really be an issue.

Yeah. I crack the side door on every start. I build the stack with this in mind.
Don't make the mistake of opening the side and front doors at the same time. Smoke may erupt.
BTW, be very careful if you open the ash pan door for extra air. You can easily crack a casting this way.
Also, please forgive our the questions about wood quality. You'd be amazed how many "stove" problems turn out to be wet wood.

 

[Simonkenton]

I have a Jotul 500. It is easy to light. The primary air design is great.
Don't know what your problem is, you might contact a priest, could be demonic possession.

 

[xman23]

As a long time Oslo owner, I concur with the OP. Jake and others explained it well. We never open the front door, due to ash spillage. That said, we load thru the side door and always leave it open to cold start. I assume you get it lit without it smoldering out. It can be a challenge to get the splits positioned just right for a quick start. I put 2 on the floor, east west and loose criss cross on top. With a fire starter between the 2 splits you create a tunnel of fire. You've done it right when the fire grows quickly, involving all the above wood. And a reload. This is with the side door cracked open. When closing the side door the reduced air flow will cause a new burn pattern, putting our some of what was burning. If it doesn't get going quickly, I reopen the side door. There is a lot of cast iron to get hot, so a few criss cross reloads are needed. But, when you get it hot and a bed of coals it's easy to run at any temperature. When it's hot, I need the air control almost all the way off. Plenty of air flow from the center holes, just needs help in startup.

 

[begreen]

@Threelittlefish, did you load the S33 E/W or N/S, or teepee style? The wood in E/W loaders like the F500 create a wall that stops airflow from the boost air port and airwash. That slows down ignition. Top-down starting helps get around this. Another way to get a quicker start is to place a pair of ~2" diameter, 12-14" long sleeper sticks down first, about 4-6" apart, at right angles to the door and parallel to the sides. Then build your starter fire on top of them. This will allow air to get under the logs for quicker starting. It's how I cold started the F400 and it made a notable improvement.