Oslo Flue Temps

[mikepinto65]

Inspired by the woodstock thread, i'd like to hear the Oslo owners normal operating flue temps. I've been struggling trying to keep my flue gasses on the lower spectrum of my Condar Fluegard probe thermometer. I have the thermo located 18" above the stove and have normal reading of 600-900 internal temps (single wall black pipe) with a stove top reading of 400-500. I have about 28-30' worth of external Class A chimney so im wondering if I might be fighting with excessive draft (is this even possible with an exterier chim?) or if this is still within safe operating temps. If its a matter of too much draft I have a stove pipe damper I can install but dont know if I should place it above or below the probe thermo.

Thanks in advance

 

[mikepinto65]

Any takers?

 

[Highbeam]

How about we morph this into a non-cat flue temps thread? My 14' vertical chimney with condar probe at 15" is acting just like yours. Normally runs 600-900 so long as there is a clean fire going and we're not down to coals, never is the flue temp below the stove temp. Last night I loaded the 400 degree stove for the overnight and with a closed primary air the flue temps sat at 850 for about an hour before settling down to 750 for a long long time. The stove temp climbed uncontrollably to 500. I hate watching the temps rise while the draft is closed. This was with large doug fir splits loaded tight for the long burn. The wife restarted from coals this morning 9.5 hours later, stove and flue at 250.

I think we both could use a flue damper but only for a bit of extra control. Doesn't seem to be required.

 

[begreen]

That seems high to me as compared to what the Castine used to run at. I was more often getting the opposite with a 600 degree stovetop, about 400 with a probe thermometer with double-wall pipe. The T6 runs cooler than you are seeing as well. Could be too strong draft, but best to get some input from Oslo owners.

 

[colebrookman]

Any takers?

For what it's worth Mike; I just use two Rutland burn indicators on the corner of the stove. Like to get the first fire of the day up to 600 or so to keep creosote to a minimum. Then usually burn 400to500, close the air in increments till almost closed. Enjoy the heat till down to 200 and restock unless it's really cold. Then I may just go to 300 and load. Right or wrong, it works for me. Be safe.
Ed

 

[firefighterjake]

400-650 degrees normal operating temp once stove is up and running . . . Condar probe thermometer in double-wall pipe

 

[mikepinto65]

How about we morph this into a non-cat flue temps thread? My 14' vertical chimney with condar probe at 15" is acting just like yours. Normally runs 600-900 so long as there is a clean fire going and we're not down to coals, never is the flue temp below the stove temp. Last night I loaded the 400 degree stove for the overnight and with a closed primary air the flue temps sat at 850 for about an hour before settling down to 750 for a long long time. The stove temp climbed uncontrollably to 500. I hate watching the temps rise while the draft is closed. This was with large doug fir splits loaded tight for the long burn. The wife restarted from coals this morning 9.5 hours later, stove and flue at 250.

I think we both could use a flue damper but only for a bit of extra control. Doesn't seem to be required.

Non-cat flue temps probably would have been better, just though i'd get plenty of response/opinions this way!
Last night I had similar reading as yours only mine hit 975 with stove top barely hitting 500. At that point I adjusted the air for the night and stove temp dropped to 400 with probe reading 750ish.
Another problem I am having is getting the stove top temp up to 500 in the first place :blank: I can build a nice thick bed of coals, add a fresh load and let it char with the air wide upon untill it burns to coal (exaggeration) without the stove top reading higher than 400. I end up having to start shutting the primary air down with stove top temps at 400 because the flue gas temp want to climb to 1000.
As I asked earlier if it is excessive draft, where should I install the damper, above or below the probe???

 

[Highbeam]

Damper right at the stove collar. Ideally, you could use an appliance adapter with a damper. You want your flue meter to read the temps of flue gasses going up the flue so you know if you are sending enough heat up the stack to keep creo away or if you are overheating it.

 

[mikepinto65]

Thanks, i'll probably throw it in tonight and see how things work out.

 

[raven]

Interesting Mike i have been thinking along the same lines. I have not burned much this season
but i think mine runs similar temps if not higher. Seems to me i can hit 1200 easy at 500 or so. My set up is 20''of single stainless to the tee and about 25' of flex . I did pick up a damper last yr but haven't installed it . Seems to me it was suggested the damper be installed 18'' off the collar . I could be wrong. One reason i haven't used the damper yet is the 20'' horizontal run to the tee . So any sound advice to the pros and cons to the damper being in a horizontal run and less than 12'' from the collar by anyone would be great . Im looking forward to hearing how the damper works for your stove

 

[begreen]

Mike, how far are you closing off the air control? Are you seeing good secondary combustion as the primary air supply is reduced? The stove top should be able to get hotter.

Before adding the damper, I would check for air leaks at the front, side and ashpan doors. Also check the glass seal and at the top gasket if the top was removed for cleaning. To make sure there is no ash build up behind the ashpan use a flashlight and a poker. Ash buildup at the back can push the pan forward against the ashpan door, preventing it from closing tightly.

 

[mikepinto65]

BeGreen, I shut the air control down 70-75% and I do see plenty of secondary combustion. I did check for leaks and came up with no on that one, in fact, if I shut the air off before the stove is up to hot enough temps needed for sustaining secondary combustion, the fire will snuff out.

 

[mikepinto65]

Just finished installing the damper....worst case scenario it dosnt work and I can remove it. I'll have to report back tomorrow as to whether or not it works, outside is a little to mild for a fire tonight.

 

[begreen]

BeGreen, I shut the air control down 70-75% and I do see plenty of secondary combustion. I did check for leaks and came up with no on that one, in fact, if I shut the air off before the stove is up to hot enough temps needed for sustaining secondary combustion, the fire will snuff out.

Sounds about right, but I would expect a strong increase in stovetop temps with the increase in secondary combustion.

A couple possibles are, the stove top thermometer is inaccurate and or the the flue thermometer is off. It will be interesting to see the effect of the damper.

 

[mikepinto65]

BeGreen, I shut the air control down 70-75% and I do see plenty of secondary combustion. I did check for leaks and came up with no on that one, in fact, if I shut the air off before the stove is up to hot enough temps needed for sustaining secondary combustion, the fire will snuff out.

Sounds about right, but I would expect a strong increase in stovetop temps with the increase in secondary combustion.

A couple possibles are, the stove top thermometer is inaccurate and or the the flue thermometer is off. It will be interesting to see the effect of the damper.

I think both thermometors are accuarate for the most part as I put the inferno on the black pipe just below the probe....i.e. probe reads 800, inferno reads 400.
Perhaps they are both inaccurate, but I really dont think this is it.

 

[logger]

I keep my stove top between 400-550. Its gotta be running hot and stacked up high enough to get the secondaries going.. still early in the season in my parts and I haven't lit her up in over a week.

 

[Highbeam]

I'm jealous of the damper setup. I wanted mine to look just like that but couldn't do it. Very curious to see how this turns out for you.

 

[mikepinto65]

Well the results are in and it seems to be working well. Established a coal bed when I got home, added wood, chard for about 10 min with damper closed about 1/4, adjusted primary air to 3/4 of the way down with firebox at 450, stove top rose to 500 where it has been for a good 60 minutes so far. Flue temps are still a little on the high side but I am now feeling powerful waves of heat rising from the stove top, enough to feel like a lite breeze and am pretty darned satisfied SO far.

 

[Todd]

Do me a favor and stick your stove top therm next to your flue therm and see what the diff is. Right now my stove is humming along at 550 with a flue temp of 600 and magnetic external is at 250. Sorry I have a cat stove, but just curious about the difference between internal and external pipe temps.

 

[begreen]

Very interesting, good to hear there's progress. Try closing the damper more. When we had a damper on the F3 and the 602, once the flue was hot and a good coal bed established, I could close the damper all the way. (It never really closes off the pipe). Just be sure to open the damper before reloading.

 

[mikepinto65]

Very interesting, good to hear there's progress. Try closing the damper more. When we had a damper on the F3 and the 602, once the flue was hot and a good coal bed established, I could close the damper all the way. (It never really closes off the pipe). Just be sure to open the damper before reloading.

Just had to do so...I filled up the stove for an overnighter and am getting probe temp of 800. Im shutting it down now to try and settle things.

 

[mikepinto65]

Do me a favor and stick your stove top therm next to your flue therm and see what the diff is. Right now my stove is humming along at 550 with a flue temp of 600 and magnetic external is at 250. Sorry I have a cat stove, but just curious about the difference between internal and external pipe temps.

Already done this many-a-time, I consistantly get half the reading of the probe with a stove top thermo stuck on the exterior of the black pipe.....ie: 800 probe = 400 stove top on black pipe.

 

[mikepinto65]

Just out of curiosity, does the warmer shoulder season temps increase or decrease draft in a chimney?

 

[begreen]

Draft increases with greater temperature differential. Warmer temps are closer to the house interior temps and decrease draft.

 

[logger]

Just out of curiosity, does the warmer shoulder season temps increase or decrease draft in a chimney?

You'll get better drafts when it cools off more. I've always noticed the colder it gets out, the better our stoves have worked.