Mansfield: Rockwool or similar substance showing 4 3/4" beneath the opening of flue collar

[Cath]

I've never actually seen Rockwool but my working assumption is that's what I'm seeing 4 3/4" below the bottom of my Mansfield flue collar. Thanks to Jonofsunderland I have an exploded parts diagram and I'm wondering if this is the ceramic blanket which is under the "top casting" in the diagram. Or whether it's a replacement, and if so whether it's an acceptable substitute. In the diagram the ceramic "blanket" looks like a rigid piece of foam but what I see looks like the smooth white poly-fill used for pillows and stuffed animals. Is this what I should see?

What strikes me is how bright white it looks against the tiny chunks of creosote or ash. The current owner says the previous owner only used it for three seasons. Should this look snowy white after that length of use?

Also, does anyone know the manufacturer's efficiency rating for a 1998 HS Mansfield? It isn't listed on the EPA site but the default rating for non cat stoves is in the low 60s. Is Hearthstone's tested rating higher?

Thanks,
~Cath

 

[Heat Miser]

There is a layer of Kaowool blanket on the baffle above the secondary tube burning assembly on my Mansfield which is probably what you're seeing. Yes, it looks like white fiberglass/polyester stuffing. It can stay white after a lot of burning. I've seen furnaces lined with the stuff running 2000+ degrees and it will stay white in appearance indefinitely based on my experience. The only time it is replaced is if it is torn or chemical flux has dissolved it. Both are conditions you are unlikely to encounter in your stove, but maybe others have experience on problems that may develop with it that I'm not aware of.

I don't know what the rating is on a 1998 Mansfield, but my understanding is the stove hasn't changed much except for a new type of handle since it was introduced. So I suspect that the rating you see on today's stoves is probably close to what the 1998 stove would be. Someone else can correct me if I'm off base here.

 

[linckeil]

i just installed a mansfield last month and i had a question regarding this material aswell and it is in regards to sweeping the chimney.

my chimney is straight up off the stove collar and through the roof. no elbows or bends in the system. when cleaning the chimney, i want to go on the roof, remove the chimney cap, and start sweeping. obviously all the creosote and grit will fall straight down and collect on this kaowool blanket. is that okay? or do i need to seperate the stovepipe at the stove and collect the sweepings so that they do not land on this blanket?

 

[linckeil]

anyone? are the sweepings ok to land on this cloth or should the pipe be disconnected to collect the sweepings?

 

[Todd]

I wouldn't sweep on top the baffle, you should be able to remove the whole baffle system before sweeping.

 

[linckeil]

ok, so you think the baffle in the stove removes? can any mansfield owners confirm that? is it easy enough to do?
that way i wouldn't have to disconnect the stovepipe.

 

[JonOfSunderland]

The baffle is removed very easily. The front baffle support (basically a piece of angle iron) can be slid to one side and dropped down. Then slide each baffle plate forward and out. Then remove the blanket. The junk from the chimney will drop around the secondary pipes and into the firebox.

You MAY have to remove the front secondary pipe for clearance (I can't remember). In which case, take out the retaining screw, slide pipe to one side (only one side gives enough room, but again, can't remember which), push the exposed pipe end UP (will have to push baffle plate up for clearance), and slide pipe over to remove completely.