New Mansfield lll observations pros and cons.

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Pinesmoke

Feeling the Heat
Dec 2, 2023
289
SE Tenn
Started learning this girl and I thought this thread could collect information on this stove.

Coming from a 18 year old non cat VC Dutch West stove this EPA stove has been a trial so far in figuring her quirks out but we are getting to know each other. The stove is connected to outside air since this house is VERY tight except for fresh air exchange in the HVAC system.

In talking to my dealer, one that I've bought multiple stoves from, he said this stove is cold blooded at startup. He wasn't kidding. Leaving the door cracked until there is a lot of heat built up has been a must or it won't take off., a half hour or so with a yellow pine fire to get things warm. Once there are some coals is good to go.

Put a appliance adapter with a damper in it when you build the stove pipe up. I've had the cat temp take off like a bottle rocket a couple of times with the intake closed completely. My stack is around 24' straight up so it will pull and having that damper is a good idea.

On temps, I asked what the max temp on the stone was and I was told 600 is considered Max. Measuring around with an infrared gun I found that the stovetop can run 100 degrees UNDER the hottest spots on the stove. The top front of the right side seems to be the hot spot. A STT thermometer showing 550 degrees may very well be well over 600 somewhere else. Something to keep in mind.

Opening the door is an act of patience or you can get a pretty good burp out of the top hinge side corner. Just sayin.
I always seem to have dirty lower corners on the glass, since the main air is coming in dead center in the front of the box. No big deal but it doesn't seem to want to burn back, even with hot pine fires.

The stove puts out good heat when she is cruising and seems to not eat wood when I've had oak in the box. I haven't had to really push it yet. The oak in an overnight burn has got lots of embers left even with the air intake cracked off of full closed.

I have the ash pan on it and the design of the shaker grate makes it pretty much useless, I took the shaker out so I can rake the coals over the open grate on the pan. Works much better.

With things to work through and learn I do like this stove. It's pretty as hell and the heat is smooth coming off of it .

More observations to come....
 
Thanks for the update. It sounds like you are getting it dialed in. What stove pipe is on the stove? Did the appliance adapter fit snugly on the flue collar, achieving a good seal, or loosely?
 
The stove pipe is DVL , double wall. The adapter isn't really TIGHT although I spread the crimps some to snug things up
 
Thanks, that's why I asked. The DVL adapter is too loose and therefore leaky on PE stoves. I tried it and now it sits on the scrap pile after I pulled out the damper. Having run the stove for years I could see the change in burning and noticed more buildup in the flue when cleaning. The damper is now in a 6" section of standard DVL which fits tightly. This is working as it should.
 
I found it interesting that the first piece of the DVL line of pipe that touches the stove was as loose as it was. I'll probably add some gasket material when I crack it for cleaning.
 
I found it interesting that the first piece of the DVL line of pipe that touches the stove was as loose as it was. I'll probably add some gasket material when I crack it for cleaning.
If the first piece is the appliance adapter, you might try fitting regular DVL to the flue collar for comparison. There is a major difference on our stove. The regular DVL seals well to the flue collar, the appliance adapter does not. I sent a note into DuraVent on this topic, but there's been no response so far.
 
Something I've noticed is that due to the center only air inlet this stove produces charcoal more that ash. My Dutch West would burn down to ash. I can rake the coals around but still have a high percentage of dead charcoal compared to ash in the pan.
 
IMG_20231228_220344611_HDR.jpg
When I'm trying to run on a warmer evening I've learned to build around the air jet. Staying one split on either side of the jet keeps a solid burn going without the heat of having a full ember bed.
 
Here are temps in what I consider a low cruise. High 30s outside with a minimal ember bed and 3 active pine splits. Air running about 50%.

IMG_20231223_203138155_HDR.jpg

STT
IMG_20231223_203148823.jpg IMG_20231223_203131385_HDR.jpg
 
The stove been hot for several days now and the cruise this girl has is pretty smooth. I still haven't had to run hard up against max temps on the soapstone but have been cruising within 150 degrees of it.

Several days back someone said they had installed one of these and OMG the cats are right under the stack so all the heat will just go up the stack. Well, with the cats running anywhere between 1100 and 1400, depending on load, the stack runs between 400-500. I don't see that as a truism. If it where the case the cat probe temp and stack temp would be much closer I would think.
 
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The stove been hot for several days now and the cruise this girl has is pretty smooth. I still haven't had to run hard up against max temps on the soapstone but have been cruising within 150 degrees of it.

Several days back someone said they had installed one of these and OMG the cats are right under the stack so all the heat will just go up the stack. Well, with the cats running anywhere between 1100 and 1400, depending on load, the stack runs between 400-500. I don't see that as a truism. If it where the case the cat probe temp and stack temp would be much closer I would think.
Obviously the cat itself will be much hotter than the exhaust temps. No other company has their cats installed this way, so far it’s proving to be problematic. I haven’t just installed 1 either, dozens rather. We have had constant service calls from clogged cats on all the hybrid hearthstones. Especially the green mountain and Manchester. Blowing heat up the flue is the least of my concern, clogged cats are though. For people on here is manageable, but out in the field, many people aren’t capable or willing to try it themselves.
 
Obviously the cat itself will be much hotter than the exhaust temps. No other company has their cats installed this way, so far it’s proving to be problematic. I haven’t just installed 1 either, dozens rather. We have had constant service calls from clogged cats on all the hybrid hearthstones. Especially the green mountain and Manchester. Blowing heat up the flue is the least of my concern, clogged cats are though. For people on here is manageable, but out in the field, many people aren’t capable or willing to try it themselves.
Yes, obviously the cats will be much hotter. The point I was making was IF the heat was being "lost up the stack" I would magine that under hard burn the stack would be significantly higher than the 450 I see. That seems to be the stack temp it runs at. If I'm on active cats, whether it's a low cruise at 1000 degrees or pushing the 1300+ range the stack is stable 400-450.

I would hope that dealers would point out these "flaws" with the cats to those who can't deal with them on their own. Hell I wish mine would have pushed me away from the EPA stove as a whole and I would have bought a real stove and been happy. I've been babysitting this girl from a warm ember start for over an hour trying to get a low cruise for the day in the high 30s. Getting a fire layed should not be a pain in my butt. It's not like I haven built 1000s of them to date. I'll report back on the cats when I get the time to pull them. They've seem more pine than oak so far. If they are an issue I'll most likely leave them out and simply burn on the secondaries and call it good. It's not like the stack never needs cleaned because they are there.

The Hearthstone is a beautiful stove with heat that is smooth as hell when cruising. Getting her in the groove can be tenuous for anything under full burns they designed to hit the regs with.
 
Yes, obviously the cats will be much hotter. The point I was making was IF the heat was being "lost up the stack" I would magine that under hard burn the stack would be significantly higher than the 450 I see. That seems to be the stack temp it runs at. If I'm on active cats, whether it's a low cruise at 1000 degrees or pushing the 1300+ range the stack is stable 400-450.

I would hope that dealers would point out these "flaws" with the cats to those who can't deal with them on their own. Hell I wish mine would have pushed me away from the EPA stove as a whole and I would have bought a real stove and been happy. I've been babysitting this girl from a warm ember start for over an hour trying to get a low cruise for the day in the high 30s. Getting a fire layed should not be a pain in my butt. It's not like I haven built 1000s of them to date. I'll report back on the cats when I get the time to pull them. They've seem more pine than oak so far. If they are an issue I'll most likely leave them out and simply burn on the secondaries and call it good. It's not like the stack never needs cleaned because they are there.

The Hearthstone is a beautiful stove with heat that is smooth as hell when cruising. Getting her in the groove can be tenuous for anything under full burns they designed to hit the regs with.
Epa stoves aren’t the problem. Particular designs are just more problematic than others. When you sell a stove it’s hard to know the skill set a person possesses, and often we have 25 stoves out there before we know of a flaw or issue someone would need to know about before purchasing. I also don’t think everyone will experience clogged cats mid season. Burning habits and flue system will make a difference I think.
 
Dropping an up date.
Last week we had no heat other than the stove and it rocked. 5ish at night mid teens during the day. Ran her pretty much at peak output. Holding the stone at 550 degrees and she just cruised, keep the place comfy.

Overnights left lots of coal from the oak load so a fast stir and a couple of pine splits and she was back to temp and ready to rock.

On the STT of the stone. The top of the stove is actually not the hottest part of the stove. The sides are the hot spots and run about 100 degrees hotter than the top. Something to keep in mind when pushing it hard.
 
Dropping an up date.
Last week we had no heat other than the stove and it rocked. 5ish at night mid teens during the day. Ran her pretty much at peak output. Holding the stone at 550 degrees and she just cruised, keep the place comfy.

Overnights left lots of coal from the oak load so a fast stir and a couple of pine splits and she was back to temp and ready to rock.

On the STT of the stone. The top of the stove is actually not the hottest part of the stove. The sides are the hot spots and run about 100 degrees hotter than the top. Something to keep in mind when pushing it hard.
Good info. I'm glad the big rock rocked.
 
Last night when I fired the girl up I noticed an interesting thing about the CAT configuration vs stack temp.

I was burning with the door cracked to get some coals built on the first load, my normal procedure and the stack was running at 600 when the cats finally got to temp. I fed her a few limb rounds of oak, closed the door with full intake air and brought the CATs online. In about 15 minutes the CATs were running at 1000 and the stack had dropped to 450.

Apparently with only the center CAT directly under the flue collar the rock is pulling heat from the 2 outside CATs. The 450 deg stack temp is pretty normal even when pushing it hard, I had never noticed the transition of the temps being so obvious before.
 
I noticed a cracked stone this morning. It's one of the small ones over the door, one of the hot spots. I have a STT guage and realize the stovetop is not the hot spot on the stove and run accordingly. I assume it's due to running close to top temps and the fact is a narrow stone. Likely a flaw or some stress put in it during assembly.

Get an infrared thermometer and get to know your hotspots on the stove.

I'll let you know how it turns out.