Hearthstone Mansfield not hot enough

[willmcb]

I have used all types of stoves;cast iron, steel, and soapstone. The guys at hearthstone got me. They convinced me to replace my vogelzang cast iron stove with the hearthstone mansfield. The vogelzang easily heated my house. I am very disappointed with the mansfield so far. It has not lived up to its claims. The stove just does not radiate heat like a steel or cast iron. I bought the slow, gentle long-lasting heat at first, but now I believe that the heat is going up the chimney. Since soapstone doesn't get as hot as steel or cast iron and takes longer to heat that leads to more heat escaping right?

 

[edthedawg]

willmcb - sounds like you're maybe having some similar issues to the OP here... what is your setup? can you share some more details about your settings and temperatures? are you backing the primary down as instructed?

this forum is littered with ecstatic Mansfield owners. you have previous happiness w/ other stoves, so i'm inclined to think you have good wood. makes me question either the setup or the operation...

 

[wellbuilt home]

I have used all types of stoves;cast iron, steel, and soapstone. The guys at hearthstone got me. They convinced me to replace my vogelzang cast iron stove with the hearthstone mansfield. The vogelzang easily heated my house. I am very disappointed with the mansfield so far. It has not lived up to its claims. The stove just does not radiate heat like a steel or cast iron. I bought the slow, gentle long-lasting heat at first, but now I believe that the heat is going up the chimney. Since soapstone doesn't get as hot as steel or cast iron and takes longer to heat that leads to more heat escaping right?

True the soapstone dose not get as hot as Cast .The soap stone pays back the heat at the end of the burn cycle . I close my damper tight and run 1/4 to1/2 air open . 1 hr before bed i load the stove , when i go to sleep i close the air and the flu down all the way . in the morning i reload . The wood needs to be very dry Ive been burning splits about 2x6 or so . last month i was sitting around under a blanket now I'm is shorts and a tee . When the secondaires kick off you will see the difference . I could not even believe the heat My stove was at 550 and i singed the hair on my legs from 2' away . John

 

[mopfoot]

Update: I tried closing both the primary and flue completely. Load has been burning for about 90 min. Secondary is definitely burning. Secondary pipes are red hot. Surface temp is only 225. Seems odd since I hear of so many like John who get theirs up to 550.

P.S. Is it bad that the pipes are red hot?

 

[Frostbit]

No doubt this has been tossed around before, but this thread brought up a question I had about surface temps (consequently, what one reads on his stove top thermometer) on a steel or cast iron stove top versus a Hearthstone or Woodstock soapstone one.

I can't help but think with a soapstone stove that the top surface temp would read much lower than, say, my Castine, when in actuality they may have the very same firebox temperature.

Am I wrong in this assumption?

If I laid a brick of soapstone on my cast iron stove top, put a thermometer on each, would at some point they read the same? I can't believe they would....

 

[mopfoot]

I looked up the BTU content of Juniper and found it to be pretty high. So I guess that shouldn't be my problem.

(broken link removed to http://www.chimneysweeponline.com/howood.htm)

 

[karri0n]

SLC, those secondaries are just fine being red hot. That's normal operation. If you closed down the primary and the flue all the way, try keeping the primary at 1/2 to 1/4 closed with the pipe damper full open. Also, make sure the full load is burning strong before damping down. If you are burning that juniper in the round rather than split, that also might have something to do with it. After 3 years of seasoning it should be pretty well dry, but rounds can be tough. For a true scientific test, try picking up 2 bundles of firewood from lowes or the grocery store, so you know you're burning good, dry, split hardwood. I think the hearthstone stoves are more sticklers for pristine wood than other stoves. You might try splitting that juniper into half rounds or even triangular splits if they're of decent size. Split wood will always burn hotter than round. Round wood is essentially for burn time rather than heat output.

 

[mikeathens]

Update: I tried closing both the primary and flue completely. Load has been burning for about 90 min. Secondary is definitely burning. Secondary pipes are red hot. Surface temp is only 225. Seems odd since I hear of so many like John who get theirs up to 550.

P.S. Is it bad that the pipes are red hot?

Mine was at 450 last night with 25 F outside. I was pretty toasty...

Try this: Get a nice robust fire going with your primary air open 50%, and your flue damper opened all the way. When the load is good and charred, close down the primary air all the way, or a little crack (maybe move the lever to 1/8" open). You should see the fire change significantly from a roaring fire to a more gentle flame, with a lot (if not all) of the flame in the top of the fire box. The burn tubes can glow red, no problem. You might even see "jets" coming from the holes in the burn tubes, sort of like a natural gas burner on your stovetop.

If you are not seeing the flame pattern change much when you shut your pirmary air, THEN crank the flue damper down some. This change in flames should be pretty apparent and pretty quick.

I have heard that some people actually have to use two dampers in the flue if the draft is super strong.

Did you install this yourself? If so, see if your dealer will loan you a draft gauge. If you had it installed, see if the installer will make a visit to test your draft for you. Also, is your thermometer smack dab in the middle of the top, middle stone?

I like the idea of trying some other wood. It could be possible, too, that your wood is too old. Could that be the case? I have some old maple that I burn occasionally. It is REALLY light and somewhat punky. I think I might be seeing the same problem as you if that all that I burned. That stuff burns fast and with not much heat. You are right, juniper is similr to cherry and walnut, both woods that I've had good results with.

Hang in there...keep trying. If it makes you feel better, I still haven't figured mine out completely yet. I have trouble with my secondaries working consistently, which I attribute to poor draft...

 

[edthedawg]

OK I guess i'll buck the trend here, but SLC - if you closed the flue AND the primary fully, i'm not really shocked about the low temp. I run hottest w/ flue damper shut full, and primary at 1/2 to 1/4. I get bigger flames w/ the damper opened, but that's just heat going up the flue... biggest flames don't always mean hottest stove...

I also keep my Rutland stovetop thermometer as far back on the stone as i can, so it is very close to the steel lip that forms the top exit collar. Like, as far back as i can get it without the magnet clicking onto the metal.

 

[mopfoot]

I'm going to post some video (probably tomorrow) to get feedback about the flames at different damper settings. I'm sure a trained eye could tell if too much air is flowing through.

I'll try to get my hands on some other wood but I'm doubtful it's the wood because it lights up just fine and it all turns red hot. I figure once wood is at that stage there's not much difference between species other than density. I'm able to easily get 8-10 hour burns with it. Just need to get more heat into the room.

Ed, that's where I keep my thermometer too. Next time my wife bakes cookies, I'll throw the thermometer in the oven to see if it's reasonably accurate.

 

[wellbuilt home]

I think your wood is wet inside, Wood doesn't seem to dry with the bark on it . I would get some good dry oak and try it . My stove doesn't really get hot on a single burn . I need to have a full bed of coals first then load the stove and look out . If you keep you ash pan 1/4 full it will hold more heat in the stove .My stove is still hot now 1244pm the next day and i never add wood today . I mite add wood now because i have to run out and wont be back till tonight . John

 

[wellbuilt home]

OK I guess i'll buck the trend here, but SLC - if you closed the flue AND the primary fully, i'm not really shocked about the low temp. I run hottest w/ flue damper shut full, and primary at 1/2 to 1/4. I get bigger flames w/ the damper opened, but that's just heat going up the flue... biggest flames don't always mean hottest stove...

I also keep my Rutland stovetop thermometer as far back on the stone as i can, so it is very close to the steel lip that forms the top exit collar. Like, as far back as i can get it without the magnet clicking onto the metal.

I agree I burn hotter with the air open 1/4 to 1/2 but if i reach above450 the air doesn't seem to matter and if i don't close the air intake i will run the risk of over fire

 

[mikepinto65]

ah - great data point! I have been looking for field experience on low-drafting flues vs high-drafting flues. Did the Heritage you used to have operate the same way for you? How high is your chimney again?

(I almost asked "how long is your pipe?" but you'll note the restraint i exhibited...)

I'm surmising that:
- Long flues = high draft = cold stove w/ primary full open.
- Short flues = low draft = WAY too hot stove w/ primary full open.

Wonder where "Happy Medium" is in that equation... we may never know (those folks don't come here to complain!)

OK, ed...I have a "flat" roof (not exactly flat, but pretty damn close). Let me try to remember this from memory...4' single wall connector into metalbestos SS; There is 12' of this class A. Of the total chimney height (16'), there is approximately 10' outside.

I have some factors working against me: I live in a narrow valley with lots of close trees (draft redustion). The majority of my chimney is exposed to outside temperatures, resulsing in reduced internal temps (more draft reduction). I've yet to actually accurately measure the draft, but I suspect I really don't want to know since I can't don anyhting about it...and leave my pipe length out of this.

I am planning an addition in the next couple years that will replace the falt roof with a 10/12 pitch gable, and give me a lot more chimney height, as well as keep most of enclosed in an insulated area.

Is your stove set up in the basement? I am considering either a woodstock fireview or hearthstone heritage. My stove will have to be placed in the basement and i'm curious as to how a soapstone will heat my first floor compared to a cast stove
btw im not ruling out the mansfield, just a little on the high end of the pricing

 

[struggle]

SLC,

Are you providing a good spread out coal base after your first load? Are you burning 24/7 ?

I just cannot figure out with a showing of secondary burn how you could not get the stove into the 450 range. Unless you have some type of obstruction in your chimney reducing draft.

My stove loaded with splits on a spread out coal bed will hit 600 in no time if not watched closely and that is with the primary shut all the way down and it will run on secondary burn for I am guessing two hours. I have never timed it. I will put a tower fan off to the side to keep the stove no hotter than 550 on the center stone. Once it hits 600 you better start opening windows or shedding clothes as the heat that comes of at 600 is really something else.

Build the fire. rake the coals out and reload it full, char the wood at good for 10-15 minutes and then throttle the primary air back and watch the center temp rise steady over the next hour or less to 450-500 range. At least it should work that easy. This is where a probe thermometer tells you where the heat is going. IF the fire is ripe roaring you can hit easily flue temps of 1000+, once I see 800 hundred on the flue temps I throttle the primary back half way and then in maybe ten minutes later shut it all the way. The flue probe will then run around usually 6-650 with a stove temp around 5-550

 

[mikeathens]

SLC,

Are you providing a good spread out coal base after your first load? Are you burning 24/7 ?

I just cannot figure out with a showing of secondary burn how you could not get the stove into the 450 range. Unless you have some type of obstruction in your chimney reducing draft.

My stove loaded with splits on a spread out coal bed will hit 600 in no time if not watched closely and that is with the primary shut all the way down and it will run on secondary burn for I am guessing two hours. I have never timed it. I will put a tower fan off to the side to keep the stove no hotter than 550 on the center stone. Once it hits 600 you better start opening windows or shedding clothes as the heat that comes of at 600 is really something else.

Build the fire. rake the coals out and reload it full, char the wood at good for 10-15 minutes and then throttle the primary air back and watch the center temp rise steady over the next hour or less to 450-500 range. At least it should work that easy. This is where a probe thermometer tells you where the heat is going. IF the fire is ripe roaring you can hit easily flue temps of 1000+, once I see 800 hundred on the flue temps I throttle the primary back half way and then in maybe ten minutes later shut it all the way. The flue probe will then run around usually 6-650 with a stove temp around 5-550

Struggle...sounds VERY similar to temps I see (except I never quite see 600 on the stove unless I relaod when it's still at 400). Big difference between you and me is many times, my secondaries are super sluggish or die out...I can't attribute that to wet wood; I'm blaming it on poor draft. Anyhow, good point about 24/7 burning. If you're letting the thing go cold between loads, then I could see not getting very hot. From a cold start (I've never really paid attention), I'll bet that it takes me two consecutive full loads to get any real heat out of my stove. She's usually still 200-300 when I get home from work (after 10 hours), and the coals are still thick.

 

[FireWalker]

I think your wood is wet inside, Wood doesn't seem to dry with the bark on it . I would get some good dry oak and try it . My stove doesn't really get hot on a single burn . I need to have a full bed of coals first then load the stove and look out . If you keep you ash pan 1/4 full it will hold more heat in the stove .My stove is still hot now 1244pm the next day and i never add wood today . I mite add wood now because i have to run out and wont be back till tonight . John

This is how I get my hottest fires.

Fill the stove and char the wood on full primary air, then run at half throttle for the rest of this burn. That 4 cu. ft. of hardwood will be down to coals in about 3 hours but your stove top should be near or above 600 and your dogs hair will now start to smell as the glass will be throwing an amazing amount of heat. Rake coals and fill again, char and set primary air to less than 1/4 and you are good for the night. If it is going to be a cold night this is how I run my stove, the first load at 6pm is sacrificed to the heat gods to get the stones hot. Once they are hot a low fire will keep the temps around 450-500 for a long time. I regularly see 300 stove top at 7 the next morning.

John, glad to hear from you, sounds like you are getting the hang of your new heater. Got any wood left for February?

 

[mopfoot]

I've been burning 24/7 since I got it (a week ago) so the stove shouldn't be too cold. I do lay the new wood on a bed of coals and it lights right up. I think draft is OK because when I restrict the primary or damper I can hear the air being sucked through.

I'll have to experiment with wood to see if that's the culprit. Thermometer may be bad. I'm wondering if stove top temperature can be influenced by room size. Does anyone have a soapstone stove that is too small for the room? How do surface temps look?

MikePinto65, for what it's worth our stove is in the basement and the heat we get from it definitely gets transferred to the main floor. Tile floors on the main that were ice cold on are now just cool. Hopefully one I get this baby cranking the tile will be comfortable and our propane will kick on less frequently.

 

[karri0n]

SLC, I still think you should try some split, dry hardwood. The Juniper very well may be dry, but with bark on and in the round it does stop drying. Logs in the round also throw a lot less heat than split logs. Firewalker's advice is probably goot to follow as well, as he's running the even more stubborn Equinox. Keep working at it, and you'll find your niche and preferred burning method and be heating your neighbor's houses in no time.

 

[struggle]

One other thought is how big of diameter pieces are you putting in the stove?

I have found if I put to large of a rounds in it burns longer put will not get much secondary. When I got my stove two seasons ago I found that most of my wood I had been splitting was to small and have now adjusted split sizing slightly larger to accommodate an all around hot fire and decent burn time.

I do load my stove though more than every ten hours. How long are you going between burns SLC?

I go about five hours during the day and refill and pack it full of larger rounds at night for the long burn. I burn mostly green ash and elm. Little to no oak around my wood grounds.

 

[mopfoot]

Logs range from 2" rounds to 6" rounds. Almost nothing is split because the logs are so small. I'll have to split some to see if that makes a difference.

If my secondary pipes are red hot can't I safely assume that secondary burn is occurring?

I load the stove up around 7AM on the coals from my overnight burn after cleaning out ashes. My wife will feed a couple logs throughout the day. Once I get home around 6pm, it's usually full of red hot logs since it's fed regularly. I let it burn off until 9PM when I load it up again. Repeat the next day. Throughout the whole day the fire is checked regularly and it is never smoldering and the exhaust out the chimney is never visible.

What color flames should I strive for? Sometimes when I close the primary, the flames turn blue. I assume that's OK since blue is hotter than yellow.

 

[karri0n]

I think blue is hotter than yellow is a misconception. The tip of the flame is generally the hottest part. That being said, blue flames from the holes in the secondary tubes is pretty common.


Just because the tubes are red hot does not necessarily mean secondary combustion is occuring. If the flames are not coming directly off the wood, but instead exist towards the top of the firebox, this is secondary combustion. There's also times when the primary combustion is burning hot enough to burn off the excess gas, and so all the combustion is occuring from the primary flames.


I would say split those 4-6" rounds, and leave anything smaller than that as is. 3" and lower will be a major pain to split.

 

[FireWalker]

Logs range from 2" rounds to 6" rounds. Almost nothing is split because the logs are so small. I'll have to split some to see if that makes a difference.

If my secondary pipes are red hot can't I safely assume that secondary burn is occurring?

I load the stove up around 7AM on the coals from my overnight burn after cleaning out ashes. My wife will feed a couple logs throughout the day. Once I get home around 6pm, it's usually full of red hot logs since it's fed regularly. I let it burn off until 9PM when I load it up again. Repeat the next day. Throughout the whole day the fire is checked regularly and it is never smoldering and the exhaust out the chimney is never visible.

What color flames should I strive for? Sometimes when I close the primary, the flames turn blue. I assume that's OK since blue is hotter than yellow.

Sometimes we make things too complex....... stovetop temps, flame color, red hot tubes, wood species or size.........

When my stove is hooooooot, the cast iron front top corner will sizzle spit on my finger and I have found this to be a good and easy test. When the stove is just crusing, you don't get the sizzle.

 

[mopfoot]

Firewalker, you're right. Some of the silly questions I asked are pretty nit-picky and maybe appear to over-complicate the issue. I'm just trying to learn but I've got the simple problem front of mind with every suggestion I've graciously been given. That problem is:

The fire looks really hot but the room isn't getting hot. Is the heat transferring to the room the way it should?

 

[willmcb]

The mansfield is on a small brick hearth in a 500 sq ft room with about 6 feet of double wall pipe to the attic. I do not have a temperature gauge or a damper yet. I plan to get them this weekend. The surface temp is not much higher than 212 because the water in my pot is barely boinling. The pros installed my stove and the draft is fine so that is not the problem. I have loaded the firebox down with oak and the fire is as hot as ever, but the room is 72 (with my other stove the room was uncomfortably warm). Once there is a hot bed of coals I close the air to 1/4 open. The secondary combusters are working. I am very impressed with how clean the mansfield burns, the burn times, and how the viewing window is cleaned on its own. The soapstone's heat is not as long lasting as I thought. It seems to cool down only slightly slower than cast iron.

The pipe radiates twice as much heat as the soapstone. The opposite happened with my cast iron.

 

[mopfoot]

Here's some video of mine after 30 min. Flue damper completely shut. Primary is almost completely closed. Does it look like it's still getting too much draft? Surface temp at this point was only 200. BTW I tested my thermometer in the oven and it read spot on.

http://www.youtube.com/watch?v=3nD5AgiUusk