Hearthstone Mansfield owners HELP!!

[RedOak]

Fellow Hearthstone Mansfield owners - I need help. After burning with a Vermont Castings Defiant for twenty years I upgraded
to a Mansfield and am having a heck of a time. Burn times are not what I expected them to be, I load with well seasoned red
oak around 9:00 after getting a good bed of coals and if I go by the stove at 1:00 or 2:00AM, all I have left is a bed of coals and
a stove that is barely 250' Also, controlling the stove is a challenge as well, the primary air control has to be placed in the
fully closed position to get any burn time out of it. I installed a damper and this has helped the situation some but I am still
eating wood like a Howitzer on D-Day.

Specifics: 20' of 8" prefab chimney, well seasoned dry red oak running 24x7 - outside temp in the 20's 30's

I am getting decent heat from this behemoth, the stove rarely goes over 500'

Soapstone is somthing I know I need to get used to, I just need a few pointers.

I won't even mention that I am on my second blower that is dying a slow very loud death....

 

[Todd]

Have you checked your door and ash pan gaskets?

 

[RedOak]

Yes, I have done all the basic stuff and I have been burning for 20+ years. The stove is brand new
and I just assume I am not used to how a soapstone stove runs. I just wanted to talk to other
Mansfield owners to see if this is the norm

 

[Highbeam]

So you load a full load of wood on top of a good base of coals in say a 450 degree mansifeld with the blower on. You leave the air open until the load is charred and then you shut down the primary air and hope for a long burn right?

Does the fire continue to rage even after shutting the primary off fully? Mine will rage for about an additional 20 minutes and then settle into a decent low burn. Clean glass after the burn.

How big are your splits? Mine cranks through the littler ones much faster than the jethros.

A nearly ideal full doug fir load in my Heritage will only last for about 6 to 8 hours before the stove is below 200 and I the coals are gone. I don't think these stoves are capable of really long burns unless you have some good hardwood.

 

[Turner-n-Burner]

I have the Morgan's big brother the Clydesdale, and I don't think your burn sounds right.



Few questions for you:

1) any chance the air control lever got damaged? It could be that you're not able to damp it down all the way.
2) are you fully loading the stove? For maximum burn, you need maximum fill. Stuff it full !
3) what size are your splits? big splits 5-6" will burn a lot longer than 2-3" splits. (a lot less work too!)
4) doesn't the manual for that stove specify a a 6" liner? 8 inch sounds awfully big for that stove...



-Dan

 

[RedOak]

Highbeam, Turner-n-Burner, thanks for the reply. I have checked the primary air shutters and they are operating
correctly - they both (there is one on the left and right of the ash pan) open and close correctly. The 8" prefab is
what I had had installed for my old Vermont Castings, I placed an in line damper to slow down what I am assuming
is excessive draft - this has helped some. I am packing it to the top with either well seasoned red oak or ash although
my splits may be a bit small for this stove - the Castings liked smaller splits.

The manual states to place the primary air shutter about half way closed. I crank mine all the way closed and have
nice clean glass in the morning. I am also getting wicked good secondary burn when I shut it down.

Where do you leave the air shutter for a long burn?

 

[struggle]

It still seems to me you are over drafting. It says in the manual you can run the stove on an eight inch liner but also states in some cases TWO dampners may be needed in certain situations.

I do not have the luxury of having oak around very often as it is not common in my wood cutting area but the splits I have used that were oak burn far longer than anything else I burn(mostly green ash, which seems to be not that hard)

If you get crazy secondary burn after dampnend down then you most likely need another dampner further up the pipe.

I loaded mine today after sifting coals and started the fire with just coals and little ash and with all the extra air space mine nailed 1000 degrees on the stack right away (probe thermometer)

The few spilts of Oak I have used if loaded at night before bed 9-10pm and settled them in to the charred state the next morning around 8AM I will have a surface temp of around 200 and stack temp the same.

I do not use a blower on mine and would think if you do then you are scrubing a lot of heat off the stove top that way as the fan I am guessing runs until the stove is mostly cold.

Do you have to use the blower? How about running a fan in the area of the stove to move heat around or one to push colder air to the stove. This is what we do.

I almost always run my dampner closed after a could fire has been established

Do you have a probe temp sensor in you pipe above the stove? If not It is a very usefull tool in telling how much heat is going up the stack. Condor makes them and they work very well.

 

[RedOak]

Actually the blower crapped out completely on Tuesday and I have been running the stove without it. It seems
to be running much better without scrubbing the heat off. The only reason I installed the blower is I have a very
open floor plan and it pushes the air into the kitchen / dining area better (or so I thought)

Question: Do you monitor stove top temps as well? I have only used that style on my Castings and it worked very
well for me. What are the benefits of monitoring stack temps? What range do you keep it in?

 

[struggle]

I monitor both center of the stove with a rutland temp quage and a stack guage. I have found using the stack probe guage you can tell right away how much heat is going out the chimney.

It helps to balance the airintake and dampner as for my set up the stove once reaching top temp of 450-500 the stack temp will match the stove temp and cruise there. One start up it can go as high as 1000 degrees on stack if not watched closely which is just a waste of heat and wood so I shut the stove back until stack temps stay around 600 or just below and once the stove tops reaches the 450 plus range then I shut the primary air mostly off and dampner usually closed.

I have my prope above the dampner. I am trying to post a picture but my host is not letting me log in.

(broken link removed to http://www.condar.com/meters.html)

I use the 3-19 model for $21. I ordered it from this site. All you do is a drill a hole in the pipe and install a little grommet thing and put it in the hole. Five minutes or less. You will spend more time getting the drill than anything else.

 

[struggle]

 

[struggle]

 

[RedOak]

Great information!! I assume your Mansfield cruises around 450-500 using the Rutland stove top?
I have not been able to get mine much over 500 - the Castings would reach 700 if not watched closely.

So if I understand correctly, I want to get the top in the 400-500 range and keep the stack temp at 600?
I had no idea I was loosing that much heat up the stack.

Gee, I'm glad the manual had all of this information in it...

 

[struggle]

Once the stove gets up to temp mine seems to show the same stove top temp as the stack temp when in the 450-500 range. Once the stove center goes over 500 the stack temp seems to rise to 600 degrees as with mine I will get a crazy secondary burn going once I get much over 525.

I can easily get the stove up to 600 degrees which it is not recommend to go over. Once you get to 600 you will be throwing I think someone said like twice the heat out that you would see at 500. It roast us out of the room at 550.

The probe will let you know what you may be losing in heat up the chimney.

If all else fails you might find that a drop in liner to a 6" diameter may be best to opimize the stove temps. Mine is running on a 5.5" flex liner as I wwould not have been able to run a 6" liner down my existing clay tile lined chimney.

A temp probe will tell you what is happening. Keep in mind it takes some time to get the stove up to that temp. LIke an hour or more depneding on how dry and hard the wood is.

Are you able to use some softer wood to get the stove going hot and then top off with Oak then? Maybe it will run hotter that way.

 

[RedOak]

Once again, thank you for the great information, I ordered the Condar probe thermometer and
hopefully this will give a hand up on taming this beast. The Castings would behave with much less
monitoring, that's why I wanted to speak with someone who actually ran a Mansfield (or other Soapstone)
I will have to install the Condar probe much lower than yours because my pipe transitions to stainless two and a
half feet above the stove, should this be an issue?

The chimney is prefab stainless steel that is only a few years old, I would hate to have to replace it
so soon with a six inch- hopefully the damper will solve the draft problem.

The pictures were greatly appreciated

And there ain't nothing wrong with 130,000 BTU's - I hate the cold.....

 

[struggle]

The probe is your best place to start. I do not think it will be a problem at all on your placement. Mine was lower to begin with but last season I had some of the thinner wall pipe (snap together stuff from Menards, thin) and I replaced that this season with the heavier guage solid welded pipe.

Update this thread when you get the probe.

 

[Turner-n-Burner]

Red Oak,
Sorry - you said Mansfield, but I saw "blowers" and somehow read "Morgan" instead of Mansfield.


Sounds like you're getting the advice you need though. Good Luck!


-Dan

 

[RedOak]

I ordered the probe yesterday and will update after I install it and get a few readings

 

[RedOak]

I installed the probe yesterday while the stove was running and got an initial reading of 1200 on the stack. Just a bit too hot.....
Seems like I have a real hard time getting the stack temp to come down once it gets high.
Sunday morning I reloaded the stove on a nice full bed of coals, stack temp went up to 1000 very quickly, closed off the damper and found that the stack ran about 200-300 degrees hotter than the stove top. Reloaded several times and found basically the same thing, stack temp on the high side and stove top in the 450-500 range. When the stove top reaches 550, the stack temp goes way hotter than I am comfortable with. I am right back to the excessive draft theory.
Here is the rest of the story - when I installed the damper in the slip joint, the bit walked and it is not perfectly centered, I can only close it 7/8 of the way down. I didn't think this would be a problem because I never thought I would have to close the damper all the way to reduce my draft. It is easy enough to buy another section of pipe and reinstall the damper. Is this worth a try?
Right now the stove that was loaded at 7:00 this morning is running at 400 with a stack temp the same.

 

[struggle]

On the initial fire of the day the stack temp on mine will run around 6-800 sometimes I hit 1000 if I walk away and do not watch it to closely.

The stack temp will stay around 600 for sometime until the stove comes up to temp and then after dampning it down further (after the wood is good and charred) it will settle in for almost the same stack temp as the stove temp or slightly less stack temp then stove temp when fully dampened down.

I seems to me if you are hitting 1200 degrees you are still having to much draft. I would with out a doubt install a dampener as far away in your stack from the other one and try that. The manual does state two dampeners may be needed in some cases and yours seems to be that way.

It sounds like the dampener is not closing all the way but another one in line will help with that. I drilled on hole on my dampener and then slid it in and tapped it with a hammer to make a center mark on the the pipe where it would exit and drilled from there. My dampener will spin 360 in the pipe.

After my stack temp reaches close to 800 I shut the stack dampner first and then after the wood chars good I throttle the stove front dampener back to let it cruise along.

Something I get when doing this after two days of burning is a pretty large bed of coals. Do you have a large coal bed after a day of burning? If not I still say overdraft.

The dampner is there to just slow the air down and not completely close it off so the second one will help you greatly I would think.

 

[RedOak]

The only problem I would have is I only have about 2 1/2 feet before I transition to double wall SS
I have to go back to the dealer to pick up my replacement fan and will pick up another section of pipe and place the damper
in correctly this time. I will ask his opinion of two dampers - originally they told me very few people have installed even one
with this stove.

As far as a bed of coals, I have plenty. When relighting the stove in the morning I have a good solid bed, the new wood catches within minutes. Same thing when I get home from work.

I agree, I think I still have excessive draft

 

[Todd]

I think the problem stems from your 8" chimney. How tall is it. Is it possible to slide a 6" liner down it? Once that 8" heats up it will pull much more than the 6" causing hotter faster burn even if your damped all the way down. If the damper doesn't work, maybe look into reline with 6"? A member here "Mountain Stove Guy" had this problem with his Mansfield and 8" chimney in his stove shop, and the Mansfield he burned at home with 6" burned great.

 

[RedOak]

Can you use a liner on a prefab SS chimney?
I will run this by the dealer when I pick up my blower, I can't be the first Mansfield owner that has experienced this problem.

I threw two good sized chunks in around 8:00 and now the stove is running about 475 with a 525 stack temp with everything closed right off. It appears that my issue is with initial firing - after a few hours it mellows out. The initial stack temp has me concerned.

Thanks to all who have responded to my questions / concerns - this forum is great...

 

[Todd]

Can you use a liner on a prefab SS chimney?
I will run this by the dealer when I pick up my blower, I can't be the first Mansfield owner that has experienced this problem.

I threw two good sized chunks in around 8:00 and now the stove is running about 475 with a 525 stack temp with everything closed right off. It appears that my issue is with initial firing - after a few hours it mellows out. The initial stack temp has me concerned.

Thanks to all who have responded to my questions / concerns - this forum is great...

That initial high temp is normal, try cutting the air back a little at reload time. 525 sounds reasonable for an internal stack temp. Figure your internal stove temp is over 1100 degrees when you see secondary combustion going on.

 

[Highbeam]

I have a simpson double wall slip section of pipe between the stove top and the ceiling supoprt box. If I was going to add a butterfly damper I would simply purchase the premade damper section from simpson, retract the slip section, and insert the damper between the bottom of the slip and the top of the stove. The little premade damper section would eliminate the chances of misdrilling. I forget if your mansfield feeds single or double wall but I know that they make this damper assy is double wall.

My previous stove was a large Lopi vented into a big masonry flue with no liner. It would behave normally until that chimney got hot enough to really start drafting and then it could easily overfire.

 

[RedOak]

To put the draft issue to rest, I talked to the facilities guys who maintain our building and they loaned me a draft meter which should fit nicely in the 1/4 hole I drilled for the stack probe. It is rated from 0-.25 wc which should put me right where I need it. The manual states anything greater than .1 wc needs a damper - I'll do several readings before I pull the rest of my hair out.