How to reduce Hearth Stone Mansfield hot coal build up

[MF1529]

I was wondering if anyone had any information/ideas on how to reduce the amount of coals that build up in a Hearthstone Mansfield. On the cold days here in Vermont I need to add wood frequently to keep the Mansfield cranking out the heat. As I do this the coals increase in depth until they are almost at the reburn tubes. I know the obvious answer is scoop them out. The problem is that I don't want to throw out all that unburned energy, and when it's burning hot it's almost too hot to remove the coals. This is definitely a draw back of this stove and I'm starting to consider getting rid of it because of this. I previously owned a VC Encore and that burned very efficently I got rid of it because it was too small. I always had white ash never large coals in the Encore. Maybe I'll switch to a Defiant, although I don't want to. Any help would be very much appreciated. Thank you in advance.

 

[Stump_Branch]

look up shawnyboys zipper method. has the same stove as you. i have tried works like a charm

 

[NH_Wood]

Don't worry - you can fix this. The cold temps do make for frequent loading and increased coals. After the secondaries have died down, open you primary air wide open and start to burn down the coals - even if you stovetop is 500* or so. In addition, I rake the coal bed to the center of the box twice during the burn down. By the time the stove is at ~ 350* or so, you should be go to go for a good sized load (8-10 splits). Give it a try and let us know how it works out for you. Also, as pointed out above, ShawneyBoy posted a method (zipper method) of piling the left over coals N/S, directly in front of the primary air. He treats the coals as a 'split' and loads new splits around the coal pile. This works very well and lets you get a good load piled in. Cheers!

 

[Wood Duck]

I have a similar problem. To combat the problem I wait until the wood is almost all coals but the stove is still very hot, then I pull the red hot coals to the front. Next I load a couple of splits on top of the coals in a way that the air coming down the glass will tend to flow below the splits and over the hot coals. This results in the splits burning from the bottom and the coals burning up at the same time. I can maintain stove top at around 450F to 500 F pretty constantly this way. With a full load of wood I might get a peak temperature of around 600F, so burning up the coals means a slightly cooler stove, but still acceptable heat output. It also means more frequent loading because I am loading only a couple of splits at a time. I still sometimes get too many coals, but this approach seems to manage the coals pretty well.

Edit: I have been watching the thermometer today and I think 400 to 450F is a more typical stove top temperature when I am burning coals. That is nice heat today when it is 30F outside, but yesterday at 10F it wasn't enough.

 

[MF1529]

Thank you to every one that responded. I am looking forward to trying out this information and seeing what happens. I will report back on the results.

 

[Rich L]

Be sure your wood is super dry.

 

[Fsappo]

I never zippered by I just open the air all the way to burn the coals down. Maintain good temps while using that energy.

 

[MF1529]

I thought I would follow up from my initial post. I have figured out a couple things from reading this post and others from the past regarding the Mansfield stoves. Most importantly I think I have set my goals a little high for this stove. I am trying to go all year without having the boiler kick on while keeping a 1700 sqft house warm and toasty. On the night the stove filled with coals it was -26 outside. I had all I could do to keep the stove pumping out heat and that meant keeping the primary 3/4 open. I am pretty sure this is the main reason for the large amount of coals, but I had to do this to keep the stove temp around 600. I was initially disappointed with the house around 62 to 65 degrees, but from reading other posts it sounds pretty normal at this temp. Burning becomes a job at those temperatures. It is very frustrating to scoop coals out of firebox that it extremely hot. The VC I previously owned definitely burned the fuel much better in this situation.

The outside temps have stabilzed and they are now 20 during the day and around 10 at night. At these temps I can keep the house 70-72 no problem. This also allows me to burn the coals down without a drastic drop in indoor temp. I have used the zipper method as suggested and found I was kind of doing it before but instead of making a row N/S I was just making a pile infront of the primary and stirring it up every half hour. The zipper method definitely helps when loading the stove with fresh wood. I have also found it increased my burn time.

As far as ash removal goes, the lack of a practical ash pan has sent me brainstorming. I bought a device called an ash dragon about a month ago. It is a metal scoop with a lid that closes before its removed from the firebox. This prevents ashes from blowing all over and coals potentially falling on the floor. I take a couple scoops out when I can and keep on burning. It was a little pricey but worth not having ash dust everywhere.

I have been thinking about switching to a VC Defiant. I think I will be happier with it as I loved the Encore but it was too small. I bought the Mansfield because people rave about it. I don't want to kick myself in the butt for making a bad switch, but I can't rave about the Mansfield. Any input on the switch?

Thanks again for all the advice.

 

[shawneyboy]

The Mansfield is a different animal. Give yourself some time with her, you won't be disappointed.

Shawn

 

[jerseykat1]

wheni get excessive coals (zipper method does not work very well for me), i crack my door and point a small fan on high into the firebox, stir every so often and about an hour or 2 later the coals have burned down to a decent level and it still generates usable heat. But i never see -26* temps here in jersey. Principle is still the same though.

 

[Backwoods Savage]

I thought I would follow up from my initial post. I have figured out a couple things from reading this post and others from the past regarding the Mansfield stoves. Most importantly I think I have set my goals a little high for this stove. I am trying to go all year without having the boiler kick on while keeping a 1700 sqft house warm and toasty. On the night the stove filled with coals it was -26 outside. I had all I could do to keep the stove pumping out heat and that meant keeping the primary 3/4 open. I am pretty sure this is the main reason for the large amount of coals, but I had to do this to keep the stove temp around 600. I was initially disappointed with the house around 62 to 65 degrees, but from reading other posts it sounds pretty normal at this temp. Burning becomes a job at those temperatures. It is very frustrating to scoop coals out of firebox that it extremely hot. The VC I previously owned definitely burned the fuel much better in this situation.

The outside temps have stabilzed and they are now 20 during the day and around 10 at night. At these temps I can keep the house 70-72 no problem. This also allows me to burn the coals down without a drastic drop in indoor temp. I have used the zipper method as suggested and found I was kind of doing it before but instead of making a row N/S I was just making a pile infront of the primary and stirring it up every half hour. The zipper method definitely helps when loading the stove with fresh wood. I have also found it increased my burn time.

As far as ash removal goes, the lack of a practical ash pan has sent me brainstorming. I bought a device called an ash dragon about a month ago. It is a metal scoop with a lid that closes before its removed from the firebox. This prevents ashes from blowing all over and coals potentially falling on the floor. I take a couple scoops out when I can and keep on burning. It was a little pricey but worth not having ash dust everywhere.

I have been thinking about switching to a VC Defiant. I think I will be happier with it as I loved the Encore but it was too small. I bought the Mansfield because people rave about it. I don't want to kick myself in the butt for making a bad switch, but I can't rave about the Mansfield. Any input on the switch?

Thanks again for all the advice.

From what you have posted, I would say you will have the same exact problem if you switch stoves! Burning the stove with 3/4 open draft first says that you will be sending a good share of your heat straight up the chimney rather than staying in the stove so that you get the benefit of the heat. Also, if you have to burn with this much draft, your wood is not the best for sure. If you have dry wood you will get better burns, will get more heat from the wood and you won't have so much of a coaling problem. The greener the wood, the more coals you will get.

In our stove, before the burn gets down to the all coal stage, we open the draft full and this will keep the stove rather warm for quite some time while burning down the coals. Then fill it with good dry wood and it takes off immediately and we have no problem reaching 600-700 degrees. We never even consider scooping out coals as that would be a total waste and like throwing dollar bills into the waste bucket.

 

[johnstra]

Whether to switch stoves is a tough call. I think you should invest more time in your Mansfield before giving up on it. I bought a new Heritage this year and then upgraded to a Mansfield because I needed more BTUs and I'm happy with the upgrade.

My place is a little over 2000 sq ft and I do keep my furnace on. It's set on 68 and it only runs early in the morning before I get up and reload the stove. If I didn't run the furnace my early morning internal temps would be in the low 60s - too cold for my wife and kids. It's only been down to -14 here once this winter, so I can see how -26 would be a workout for the Mansfield - especially without a backup heat source. I was able to keep the stove room right at 70, but the rest of the house was pretty cold.

If you have good wood, your best heat output from the Mansfield comes with the primary air closed down. I close mine all the way and get strong secondaries for about 3 hours. Stovetop temps right at 600. After 4 hours on cold nights I open the primary air up to start burning the coals. I have a lot of pine, so I alternate loads of that and oak and I don't have trouble dealing with coals.

What is the layout of your home and how well insulated is your house? 80K BTUs should be able to heat 1700 sq ft pretty well.

 

[fire_man]

I was wondering if anyone had any information/ideas on how to reduce the amount of coals that build up in a Hearthstone Mansfield. On the cold days here in Vermont I need to add wood frequently to keep the Mansfield cranking out the heat. As I do this the coals increase in depth until they are almost at the reburn tubes. I know the obvious answer is scoop them out. The problem is that I don't want to throw out all that unburned energy, and when it's burning hot it's almost too hot to remove the coals. This is definitely a draw back of this stove and I'm starting to consider getting rid of it because of this. I previously owned a VC Encore and that burned very efficently I got rid of it because it was too small. I always had white ash never large coals in the Encore. Maybe I'll switch to a Defiant, although I don't want to. Any help would be very much appreciated. Thank you in advance.

I took a look at the specs on the Mansfied and the VC stoves:

Mansfield 80,000 BTU 2,500 sq ft 3.2 cu ft 6"
VC Defiant 60,000 BTU 2,400 sq ft 3.1 cu ft 8" Non-cat model
VC Encore 50,000 BTU 1,800 sq ft 2.1 cu ft 6" or 8" Non-cat model

Looks to me unless the manufacturers are playing numbers games, the Mansfield wins the race. Two big negatives for the Defiant are it
takes an 8" flue and it uses Neverburn technology. From what I read neverburn is good if you like pulling your hair out in large clumps.

Seems odd how much bigger the Defiant's box is compared with the Encore but it's BTU's are not much higher.

Was your Encore an Everburn stove or a cat stove?

 

[MF1529]

My Encore was a cat stove and that allowed me to open the primary air much more as the exhaust has to pass through the cat chamber before it exited the chimney. I had previously viewed all the BTU info from the encore, defiant, and the Mansfield. That is why I was disappointed with the low heat. It seems to me that burning a soapstone stove takes time to learn what works best. The more I read from everyone ,I'm starting to think my wood is probably not dry enough. I split it in the fall of '09 and the spring of this year. Despite the time the wood will occasionally hiss so I guess that should be a clue for me. I'll have to wait till next year to ensure my wood is very dry. Thanks for all the beneficial info. This site is great!!

 

[ckdeuce]

I bought the Mansfield because people rave about it. I don't want to kick myself in the butt for making a bad switch, but I can't rave about the Mansfield. Any input on the switch?

Thanks again for all the advice.

Not sure what is going on with your stove. My Mansfield keeps my 3000 sq' home nice and warm without any problems, and I have some wood that is not the best. Keep trying because we love ours and it is up for the challange. Some of my distant rooms stay cooler low 60's but the rest of the house has no problem mid 70's. We have two sets of stairs going to the second floor, one at the front of the house and one at the very back. That might play a role in letting the war air upstairs.... Who knows.

Don't give up yet.

 

[IdahoRenegade]

IMO, if you're running your air intake 3/4 open (except at startup) you're wasting a lot of heat and wood. The beauty of the Mansfield is the thermal mass. I find loading the firebox completely, getting a good burn going, then shutting the air all the way, or nearly all the way down, puts out the most heat with the least wood used. Just make sure you're getting good secondary combustion. Let the wood burn down till it's nearly out, the mass of the stove will keep the room warm for a good, long time. When it's in the low teens, 3 good loadings (morning, mid day and before bed) keep my 2100 SF home nice and warm.

I typically don't see the -26 you mention, but with -10 to -20 degree temps, I do about the same, just load a bit more often to keep the stove temp up. I think you'll find a real difference if you keep your air intake shut down. Running with it open both takes more heat out of your firebox and up the chimney, but also sucks more heated air out of the room (assuming you don't have an outside air intake).

IMO, these stoves don't like to be run with just a small load of fuel with one or two splits tossed in frequently. You need to run the air intake much more open to keep a nice burn going that way. It took me some playing to figure that out, and I still haven't been able to train the wife on that. I find loading the box conveniently full, then letting it burn with the intake shut down, both kept me warmer and dramatically reduced wood usage. I go through about 3 cords a winter, burning 24/7. That's with poor wood by eastern standards, I burn mostly Doug Fir.

Having said that, houses and fuel varies, ymmv. I wouldn't give up yet, good luck.

How well insulated is your house? With reasonable insulation and decent wood, I would think your Mansifeld would keep a 1700 sf home nice and toasty.