Diary of a Surdiac

Here we go. Dec. 1st, and the stove is running. Started last nite about 8pm, and after a little smokey wood fire, the Coal Contractors coal was all lit and the hopper was filled by 9:30pm. Seems the initial thermostat adjustments were off compared to normal running. Usually I never needed to set it much above 1, and alot of times, it was below 1, but to keep it running last nite (B4 bed), it wanted to be set as high as 2, or the coal bed color would die down to a dull red. Now that it's been running the nite, it seems to have settled back down to around 1.Set my MPD (almost fully closed) to adjust the manometer down to .04. Went to bed about 1am, and woke around 8am to a warm upstairs hallway. checked the fire, and it was burning brilliantly, (almost too hot), even tho visually looking under the grates thru the open ash pan door, the grates appeared to be clogged. (No red glow underneath).If the "Santa" coal was in the pit, the fire would've been almost dead. Go figure.
Outside temp in the 30s today, and currently the house is a warm 74 downstairs, and 80* in the upstairs hallway. Oil tank is a little less than 1/2 full. Let's see if I can get thru Dec. W/O needing a refill. Now begins the Christmas rush. Hope everyone's prepared. Enjoy.

Joeq,welcome to the 2013,2014 burning season well I had some Mammoth form Coal Contractors last year and all I can say is wow,burns hot as hell with a real low % of ash.I will fill up next year with it after I finish the 3 tons of Harmony I have left.Take care and enjoy the warmth .Keepaeyeonit

Thanx KY. I'm not understanding the "Mammoth form" coal contractors. I'm having a bear of time finding it here in Southern N.E. Should I be looking under something else?

Sorry,bad spelling should be "from" not "form" my dealer calls it Mammoth(from the Mammoth vain? I'm not sure)but he gets it from Coal Contractors and it good coal.

Well, I'm glad to hear they're still operating. I'll have to give them a call again this week.

Well, here it is, a week before Christmas, and all the optimism towards this new brand of coal (Coal Contractors), is waning really fast. At 1st, the burn times seem to be increased over the Blaschac. But after burning strong for a week, everything started to peter out. Back to an "almost" dead fire after only 4-5 hrs. (Sleep time...no tending). after finding the exhaust ports at the top Lefthand and right hand side of the firebox almost clogged with ash, and applying a thorough vacuuming to every square inch of the stove, back to burning again, with the hopes of the clogged ports being the culprit. But once again, the same results after a week. A buddy of mine, burning the same bagged pea coal, was having a problem with his taking off. I guess I'll be fighting with this stove the rest of the winter, and will only be using it sporadically, till it will take a hike next summer. Probably be looking for a more desirable candidate.

Once again, while scouring through countless threads on this site, I've come across some more pertinent info regarding coal burning. My stove manufacturer recommends a baro, but my installation makes this "difficult." (Due to the lack of pipe behind my stove). So I've installed an MPD, and it seemed to help immensely. however, over time, the stoves bad habits have returned. (Short burn times). I'm beginning to wonder if it "wasn't" the fault of the brand of coal, but the ash clogging of the stove. I keep finding "new" areas of ash accumulation, and yesterday found another one, because of a comment made by Gregg in the thread in the MPD VS Baros. He stated that when running the MPD almost closed, ash will accumulate around it, and sure enuff, when I checked mine, it was excessive. Could this also be the culprit, causing my stove to die prematurely? I cleaned it out yesterday, but the outside temps are so warm right now, it'll be off till after Christmas. It makes sense that the stove works fine the 1st week of burning, then diminishes over time. If this ash clog seems to be another thorn in the system, maybe a baro will be next on the "to do" list.

Yeah, interesting... The symptoms you described remind me of a time when I had similar problems. Fire would run good for about a week, then it seemed they wouldn't hold up for a 12 hour duration like before. The problem I found was that my primary air was finding a better path to take, instead of up thru the coal bed. I discovered passage ways in the front and rear liner of the coal bed that allowed primary air to become secondary air. It would work good for about a week and then, (due to ash accumulation around grate frame) primary combustion air would take the path of least resistance around the coal bed about midway thru the burn as ash accumulated on the grates.

It was a huge triumph when I realized this. I ended up stuffing fiberglass insulation in the bypasses between the fire box wall and liners. For me it was quite the revelation. It gave me back my 12 hour steady burns and more heat for the same coal usage.

As for the dampers, It's hard saying if they will impact your outcome on this issue. I think a barometric is better at maintaining a steady draft pressure which may give you a more user friendly coal experience

Maybe every few days with the hopper real low or with the hopper empty, and a hot fire going, damper open, open your door and work the heck out of one half of the stove, getting all the ash from the one side. Then get that side burning good again by adding coal onto that half, then do the other half. You'd have to figure out the best way it works for you. I usually do the whole stove when I do it but if you do half at a time it wont go out. I lost a couple fires learning how to do it but don't have it happen anymore. it might take quite a while to get the half going again, or maybe not. A heavy poker with a bent flat side is what I use when I see a lot of ash buildup. Slicing just doesnt get it all.

Lee, I was wondering if secondary air would've actually helped my stove, cause when my grates (below) would clog with ash,(overnite) and not allow air to pass thru, then if the air had somewhere else to "bypass" the clogged grates, the fire would burn a little longer(?) However since this Coal contractors coal has been burning, it "appeared" to run longer, "with" clogged grates. (Just not long enuff), after what appears to be ash accumulation on the "exhaust" side.
Warmin, I'm not sure where you're going with cleaning half of the coal bed at a time. My concern (now) is keeping the ash from collecting in my exhaust ports up inside the firebox, around the "almost" closed MPD valve, and the pipe outside at the cleanout 90* bend. These are the areas that now seem to have been my restriction, but as of right now, can't prove it, till the cold comes back, and I start burning again. I'll keep you posted if anyone's interested.

joeq wrote:Lee, I was wondering if secondary air would've actually helped my stove, cause when my grates (below) would clog with ash,(overnite) and not allow air to pass thru, then if the air had somewhere else to "bypass" the clogged grates, the fire would burn a little longer(?)

IMHO no.... seconday air goes in over the coal bed and doesn't do much to burn the coal, It helps to burn the volatile gases off the top of the coal bed. I don't think it would help this situation.. UNLESS the secondary air is helping with draft THEN yes it would help.. But that would mean the problem is a drafting problem, not an ash choking problem.. You have a manometer installed?

joeq wrote: Warmin, I'm not sure where you're going with cleaning half of the coal bed at a time. My concern (now) is keeping the ash from collecting in my exhaust ports up inside the firebox, around the "almost" closed MPD valve, and the pipe outside at the cleanout 90* bend. These are the areas that now seem to have been my restriction, but as of right now, can't prove it, till the cold comes back, and I start burning again. I'll keep you posted if anyone's interested.

What Im talking about is in addition to your slicing. I am thinking that ash may be getting deep in the corners and your slicing isnt getting it all. Then there is no under grate air to burn the coal, so it slows down your burn. Half at a time so you don't put out your fire as working it hard with a poker can put it out.

Or, it could be the ash buildup you are speaking of.

Lee, I do have a manometer, and set it where Surdiac recommends, (approx. -.04). I'm just wondering when the ash accumulates through the nitetime hrs, it (the draft) slowly goes away.
And Warmin, I think I see what you're getting at, by cleaning the grates while the fire is still burning.
my question to both of you is how often do you need to remove ash accumulation, not only in your burning coal bed, but inside your pipes around your dampers? Not sure of your set-ups, but I think I remember you (Lee) having an MPD. Do you run it mostly closed, and does it clog up frequently during the burning season? Or can you make it through the winter? Once again, I thank you guys for your advice.

joeq wrote:Lee, I do have a manometer, and set it where Surdiac recommends, (approx. -.04). I'm just wondering when the ash accumulates through the nitetime hrs, it (the draft) slowly goes away.

Yes, it very well could be but the cause could be a few different things. It sounds like ash build up since the symptoms reappear after a week, the bypassing air condition I brought up earlier.. It could also be that once the coal bed accumulates some ash that can't be cleared (like around the grate frame) you need to set your primary air a little higher to compensate. And also, if you are getting a yoyo effect of draft pressure causing variable heat output the barometric damper may help aid all of this. SO, don't try to fix everything at once.. Take one possibility at a time and do your best to fix it. Sometimes it takes some trial and error

joeq wrote:my question to both of you is how often do you need to remove ash accumulation, not only in your burning coal bed, but inside your pipes around your dampers? Not sure of your set-ups, but I think I remember you (Lee) having an MPD. Do you run it mostly closed, and does it clog up frequently during the burning season? Or can you make it through the winter?

Normally, fly ash in the pipe only needs to be cleared halfway thru the heating season and then again at the end of the heating season for a hand fed. I have a MPD but only use it occasionally. I'm a baro believer, I rely on the baro 99% of the time. Its the automatic regulation of the draft pressure I spoke of earlier that may help your issue. You said you set draft pressure at -.04 you use the MPD to do that? MPDs aren't good at holding a set pressure. As the chimney cools after burn off of volatiles, the draft weakens. This is when the MPD would need to be adjusted back to -.04 otherwise it will continue to decline since its a "fixed" restriction. I know that got hairy lol but that's the nuts and bolts of it.

joeq wrote:Set my MPD (almost fully closed) to adjust the manometer down to .04

I went back a few posts to try to help identify the issue. I am more confident now that the issue is draft pressure falling thru the nighttime.

joeq wrote:To maintain my draft @ .04-.05, my MPD is almost completely shut, and the stove thermostat is set at 1

As the chimney is cooling, your draft is likely falling which will cause less combustion air. Is the combustion air automatic? Does it open as the stove temperature falls? If not, I believe this is a bulk of the problem and a baro should be a huge improvement.