Where is the air intake on a Jøtul Oslo F500?

[David S. Lynch]

I cleaned all the creosote out of the used stove I bought, replaced all gaskets, blacked the stove and gave it a test firing outside. However, the only way I could get the stove to draw was to open the ash drawer door. Normally, that creates way too much draw and would overfire the stove. In this case, it didn't, and every time I closed the door, the fire was smothered - even after I got the fire going and the stove and stove pipes were good and hot, and seemed to be drawing fine.

I suspect that the air intake is clogged. It's either that or my temporary stove pipe configuration was poor and caused the problem (see photo link: https://www.dropbox.com/s/p326s5h920x8gn5/StovePipe.jpg?dl=0).

I removed the inspection cover just inside of the door, and the air valve is working and looks unobstructed from there. But where is does the air intake originate for that valve? Is it on the bottom of the stove? I need to find that end of the air feed and make sure it is unobstructed, too.I'm hoping it was my funky stove pipes not being vertical enough and not the air intake, but I've test fired my old Oslo with no stove pipe and it drew better than this!

 

[Stinkpickle]

Stack not tall enough, maybe?

 

[claydogg84]

I'm pretty sure the intake hole is on the bottom of the stove.

 

[David S. Lynch]

STILL CAN'T GET THE STOVE TO DRAW

OK, found the air intake, reversed shop vac and blew air through it, and could feel it coming out the three jet holes on the air valve cover. I also removed the air valve cover and vacuumed out the intake there. I still can't get the stove to draw! On my second firing, I set up a more reasonable temporary stove pipe.

With the ash door open it should be like a ram jet, but it is more like a normal fire. The stove has heated up and the pipe is venting well. It is firing well with the glass door open. But if I close all the doors, the fire is choked out within a minute.

Again, I've done test firings like this with my old stove - in similar conditions, 60° day - and without any stove pipe, and it drew well enough.

When I bought this stove, it had been either underfired or fired with pine and was full of creosote. I cleaned the stove thoroughly and inspected everything except the tubes. Could they be the problem?

 

[claydogg84]

The tubes won't keep the fire from burning. Just curious, are you using good dry wood?

 

[begreen]

Could be weak draft, especially when the outside temp is mild. Describe the complete flue system, from stove to chimney cap including elbows, tees and length of the stove pipe and chimney runs.

The Oslo likes a decent amount of draft. I'm surprised to hear one without a stove pipe would draw much at all. But perhaps there is negative pressure inside the house at the stove location that is compounding the issue?

 

[David S. Lynch]

The tubes won't keep the fire from burning. Just curious, are you using good dry wood?

Yes - in fact, on this last firing, I added bone-dry pine so I could rule out the cherry I used on the first firing (though it is also good and seasoned). And I've burned the cherry in my finnish wood stove and it fired up perfectly.
Everything is burning so long as either the front door is open or the ash drawer is open. Again, when the ash drawer door is opened, it usually creates a ram-jet-style overfiring that you want to avoid. But with the ash door open the wood burns at a normal pace, which is strange.

 

[David S. Lynch]

Could be weak draft, especially when the outside temp is mild. Describe the complete flue system, from stove to chimney cap including elbows, tees and length of the stove pipe and chimney runs. The Oslo likes a decent amount of draft. I'm surprised to hear one without a stove pipe would draw much at all. But perhaps there is negative pressure inside the house at the stove location that is compounding the issue?

BG: I'm burning it outside for a few firings to smoke off the stove black. Here is a link to a photo of the setup: https://www.dropbox.com/s/uvkcgeafmbfrvma/StovePipe2.jpg?dl=0
I'm hoping you're right and it's simply the short stove pipe I'm using temporarily. But I'd hate to get it hooked up inside (where I will be venting it through a very long flue), and find out it still doesn't draw.

 

[begreen]

That is the issue. The Oslo is not going to draft well with a short piece of pipe. Nor will many modern stoves. Once it is connected to a proper stack that has at least 16' of vertical stack it should draw well. You probably already know this but we see too many cracked bases on Jotul stoves where the owner has used the ash pan door as an air intake. It's a common way to damage the stove.

Just curious, was the "old Oslo" actually a Jotul F8?

 

[David S. Lynch]

That is the issue. The Oslo is not going to draft well with a short piece of pipe. Nor will many modern stoves. Once it is connected to a proper stack that has at least 16' of vertical stack it should draw well. You probably already know this but we see too many cracked bases on Jotul stoves where the owner has used the ash pan door as an air intake. It's a common way to damage the stove. Just curious, was the "old Oslo" actually a Jotul F8?

Yes, I am well aware of the havoc an open ash drawer can wreak on a stove. In the past, I have cracked it open a tiny amount for 30 second intervals to start a stubborn fire, but that's all. I was surprised I didn't get that ram jet effect for these outdoor burnings.

The old Oslo was an F500 as well.

 

[branchburner]

OK, found the air intake, reversed shop vac and blew air through it, and could feel it coming out the three jet holes on the air valve cover.

When I bought this stove, it had been either underfired or fired with pine and was full of creosote. I cleaned the stove thoroughly and inspected everything except the tubes. Could they be the problem?

So if the air intake provides both primary and secondary air, you have only confirmed a clear pathway for the primary air. I believe that even wwithout secondary combustion ocurring, a major source of air for your firebox is going to be through the secondary tubes as well as your primary. Maybe try blowing air through the intake with the primary fully shut and see what is coming through the tubes?

(BTW, creosote may result from the stove being under-fired but does not come from being "fired with pine" but frather rom wet or green wood, whether pine or not.)

 

[begreen]

Yes, I am well aware of the havoc an open ash drawer can wreak on a stove. In the past, I have cracked it open a tiny amount for 30 second intervals to start a stubborn fire, but that's all. I was surprised I didn't get that ram jet effect for these outdoor burnings.

What you're experiencing is quite normal. I've broken in a few stoves outdoors with a 4 ft pipe during milder weather. All were quite lackluster in performance and required the main door to be left ajar in order to not snuff out the fire.

 

[David S. Lynch]

What you're experiencing is quite normal. I've broken in a few stoves outdoors with a 4 ft pipe during milder weather. All were quite lackluster in performance and required the main door to be left ajar in order to not snuff out the fire.

OK, thanks. I'll stop fretting and install it in the fireplace flue.

 

[firefighterjake]

Yes, I am well aware of the havoc an open ash drawer can wreak on a stove. In the past, I have cracked it open a tiny amount for 30 second intervals to start a stubborn fire, but that's all. I was surprised I didn't get that ram jet effect for these outdoor burnings.

The old Oslo was an F500 as well.

Well seasoned wood plus a Super Cedar and you should never need to crack the ash pan door again.

As mentioned ... your stove pipe was too short to get a good draft going.