Hearthstone Mansfield overheating flue temps

[bubela]

I'm running out of the larger splits of wood (aprox 6" diameter logs/splits that are seasons 3 years), and have started burning smaller splits, (aprox 3" diameter with about a year of seasoning). I split these smaller pieces for another stove I have at work, but thought I'd use them to get through the winter since they are plentiful. The problem I am having is: If I fill the stove with them, it sends way too many flames up the stovepipe. I do not have a flue probe in the stack for temps, but will be installing one in the near future.

If I only half-fill the Mansfield, the temps seem to be in order. It's only when I go for the overnight burn that it gets too hot in the flue. I woke up last night about an hour after filling the stove with these smaller splits, to the smell of burning dust/paint off the pipe. (not sure which it was exactly).

My question is; would a stove pipe dampener help me with this issue? At the time that the flames were going up the chimney, the Mansfield surface temp was only 350 F. Any other suggestions, worries, etc?

 

[edthedawg]

pls give us the rundown on the chimney specs again? thx.

-Ed

 

[chunkyal]

I have a similar problem with my little wood burner. I burn all softwood so if I let it get away even a little - 700F easy - fully choked. Just installed a flue damper today and it does seem to "throttle" the flames a little - but not as much as I expected. The damper I installed looks to block about 85 - 90% of flue area.

24' chimney total, 14' single wall inside, 6" dia.

 

[bubela]

Chimney is 4' of single wall stove pipe out the top of the Mansfield
90 degree and through the wall to a stainless double (or triple?) walled pipe
another 90 degree (with cleanout) and up about 15' more.

 

[FDUTTON]

I'm running out of the larger splits of wood (aprox 6" diameter logs/splits that are seasons 3 years), and have started burning smaller splits, (aprox 3" diameter with about a year of seasoning). I split these smaller pieces for another stove I have at work, but thought I'd use them to get through the winter since they are plentiful. The problem I am having is: If I fill the stove with them, it sends way too many flames up the stovepipe. I do not have a flue probe in the stack for temps, but will be installing one in the near future.

If I only half-fill the Mansfield, the temps seem to be in order. It's only when I go for the overnight burn that it gets too hot in the flue. I woke up last night about an hour after filling the stove with these smaller splits, to the smell of burning dust/paint off the pipe. (not sure which it was exactly).

My question is; would a stove pipe dampener help me with this issue? At the time that the flames were going up the chimney, the Mansfield surface temp was only 350 F. Any other suggestions, worries, etc?

I went thru the same thing last year, I would pack it full of small splits and the stove pipe temp would hang around 550* for about three hours, it never went higher and the primary air was off. I checked my stove temp vs my pipe temp last week and they were very close. Good luck

Frank

 

[edthedawg]

Yeah that's kinda crazy hot for a shorter stack. The single-wall section - any way to monitor the surface or internal gas temps? I would expect a damper to help you - yes. But we've seen a number of damped stoves lately w/ heavy creosote buildup, so just beware that you will still need to run it "wide open" for at least a little while every day...

Pack those little splits tight during loading and that might help reduce their burnrate a little. Reduce the surface-to-volume ratio of the fuel and it should burn a little cooler, a little longer.

Good luck!

 

[chunkyal]

I might get boo-hooed for this but a few chunks of wet stuff helps keep things under control for me.

 

[Highbeam]

When you stoke for the night you are shutting the primary completely off aren't you?

If so, and if the fire is a ripping inferno after a good half hour of being shut off then you would benefit from the damper enough to put one in ASAP.

 

[rydaddy]

Given my experience, which is worth all of about 1.5 cents... Could be your draft is so great that when burning smaller pieces of well seasoned wood you're getting over-fire temps? I've noticed with mine some similar issues as yours. These are definitely less than perfect beasts aren't they? I also will mix greener wood with dry wood as an added temp controller.

 

[bubela]

Edthedawg, I’ll be installing a flue temp sensor shortly. Probably at the same time I install the damper. I’ll run it wide open every morning to get the stove up to temp. Takes at least a half hour, sometimes an hour to do so.

Chunkyal, interesting idea. I might try that if I’m still having the problem after the flue install.

Highbeam, yes primary is completely closed at nights. Primary is fully closes most of the time really. I make sure the door and ashpan are tight as well, even though I never use the ashpan to remove the ashes.


Just so I’m making myself clear. The large splits of wood, that were seasoned a good three years, worked in the Mansfield perfectly. I’d throw 4 or 5 (depending on how many I could stuff in) and it would burn perfectly for 8 hours until coals, throwing off 400-500 surface temps. It is these smaller, year old splits that are burning WAY too hot (when stuffed full in the stove).

Right now we’re having a warm spell, and I’m just ¼ filling the stove and it’s working well. Getting a decent burn time to boot, aprox 6 hours.

 

[rydaddy]

You know, I have often wondered why they don't make my stove (Heritage) with just a fully open or fully "closed" option. I NEVER have it in between. You're not alone.

 

[struggle]

I am burning smaller splits as well from time to time and the dampener is a must as well as the temp probe.

I now split bigger pieces for this stove but am still burning stuff that I had prior to getting this one. The small stuff on a solid bed of coals burn up like raw gas.

 

[edthedawg]

I run the Heritage in lots of mid-range primary settings. Some of the hottest fires achievable are with the primary set about 1" away from full-closed... Pretty sure HighBeam is of similar sentiment on that....

 

[Highbeam]

You betcha, if it isn't about an inch or so from closed then she aint going past 475. There's a whole lot of heat to be had between 475 and 550 or for those daredevils right on up to 599. At 600 she turns to dust. Every night I run for 9 hours with the draft fully closed and the stove predictably runs up to 450 and then cruises. I find it extremely comforting to be able to depend on the stove to respond in a predictable manner when I go to bed.