Question about maintaining a fire

Question about maintaining a fire

PostBy: Jaeger On: Tue Mar 03, 2009 11:52 am

Greetings,

I just registered yesterday and have learned a lot about heating with coal from searching this great site. I followed the instructions on "how to build a fire" and can do it without a hitch. My problem is I seem to be getting plenty of practice!

The longest I've been able to maintain a fire is for 4 days (Wed. afternoon the 25th-Sun. AM the 29th). I relit Sunday (1pm) and it was out Mon. AM. We got a good snow overnight (for the area)Sun. with high winds 35+mph and it was cold (17deg) Monday AM fire was out. I relit yesterday (1pm) and it ran great, like it always does until 530am when I got up and checked it and it was out. I switched back over to oil and am using it now.
It is currently 19 deg with 11mph winds. The weather conditions (high -low, and barometer) for the days I was using the boiler are:

24th: afternoon H 38, BARO 29.47
25th: H49-L17, BARO 29.52
26th: H60-L30, BARO 29.41
27th: H56-L39, BARO29.30
28th: H38-L30, BARO 29.00
1st: H39-L35, BARO 29.23
2nd: H22-L17, BARO 29.00

I'm using a Harman SF360 hand fired boiler that is hooked up to my homes 2 air handlers, 60 gallon indirect water heater and radiant floor heat. (about 2000 sq ft. radiant)

I use wood and nut coal to start and then feed it with stove coal. I'm thinking that my draft is too good (when I opened the doors to clean it all the dust goes right up the chiminey) or my coal is too big. The stove coal is 2x as big as the nut and does not lay as nice when piled in the stove (much more air space around each piece) My flue is about 45' high and 8" in diameter. My water temperature runs between 140-180. The aquastat is set at 160. My automatic draft control opens at 160 and shuts at 180 (the boiler usually runs around 170 when it's running good). I've closed the vent on the draft control (vent on the draft flap that rotates to expose (2) 3/4" holes) to about 1/4 open for when the draft flap is closed. After spending several hours on the forum this morning I'm thinking I may need to close the draft control more (the flap that opens to allow air in to bring the temp back up). I'm worried that I'll choke the fire out if I do. understand a little more about the draft but am definitely doing something wrong. It is a little frustrating but I know there is a big learning curve for me, especially now that it's cold.

Sorry for such a long post but I wanted to provide as much detail as possible for you guys who forgot more about heating with coal than I'll ever know. Thanks in advance for any insight you guys can provide...............J
Jaeger
 
Stove/Furnace Make: Harman
Stove/Furnace Model: Trident Boiler model SF360

Re: Question about maintaining a fire

PostBy: Devil505 On: Tue Mar 03, 2009 12:13 pm

Jaeger wrote:The longest I've been able to maintain a fire is for 4 days


What happens after that? (is it just dead?)

Couple of question:

1. Are you filling the firebox FULL with coal?
2. Do you have a barometric damper?
3. What temp are you running it at?
4. What type of chimney & height?
Devil505
 
Stove/Furnace Make: Harman
Stove/Furnace Model: TLC-2000

Re: Question about maintaining a fire

PostBy: Jaeger On: Tue Mar 03, 2009 12:42 pm

Thanks for the quick reply!

When I get up it's like an old bbq grill that you used the day before. I still have some good size chunks of burnt coal (no black) but when I shake it it has a tiny bit of red still inside. Not enough to get going though.

I add coal in layers throughout the afternoon and fill it before bed to the fire brick. (I shake it until little red coals drop just before the bedtime fill)
Just a regular damper no adjustments or anything attached to it.
Boiler water temp is between 140-180, I'm going out today to get a magnetic thermometer for the flue.
Metal pipe for about 4 feet from the boiler to the wall and about 40 feet of flue tile (8" sq) to 4' above the roof.

Any help will be appreciated!!!..............Jaeger
Jaeger
 
Stove/Furnace Make: Harman
Stove/Furnace Model: Trident Boiler model SF360

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Re: Question about maintaining a fire

PostBy: Devil505 On: Tue Mar 03, 2009 12:52 pm

Devil505
 
Stove/Furnace Make: Harman
Stove/Furnace Model: TLC-2000

Re: Question about maintaining a fire

PostBy: Devil505 On: Tue Mar 03, 2009 1:10 pm

Jaeger wrote:I add coal in layers throughout the afternoon and fill it before bed to the fire brick. (I shake it until little red coals drop just before the bedtime fill)


Not sure I understand??

You fill it TO the firebricks or TO THE TOPS of the firebrick?

You should always fill it completely (to the top of the firebrick)

Why just layers in the afternoon??

(sounds like you are making allot of extra work for yourself! :)
FILL ER UP! :lol:
Devil505
 
Stove/Furnace Make: Harman
Stove/Furnace Model: TLC-2000

Re: Question about maintaining a fire

PostBy: Freddy On: Tue Mar 03, 2009 1:44 pm

I'm betting you do not have a barometric damper and on windy days the coal burns too fast, the heat goes up the chimney, and you end up with an outfire.

Filling a coal stove is like filling the gas tank of your car because you want to go faster. :) Obviously filling your gas tank doesn't make you go faster, it makes you go further. Burning coal is similar, but, it has an advantage. For some reason coal likes to be deep. A nice deep fill will burn better than a thin layer. Once it's filled you control the "speed" by controlling the incoming air.

So, do you have a barometric damper?
Freddy
 
Stoker Coal Boiler: Axeman Anderson 130 (pea)
Hot Air Coal Stoker Stove: Reading piece o' junk in the barn (rice)
Coal Size/Type: Pea size, Superior, deep mined

Re: Question about maintaining a fire

PostBy: JB Sparks On: Tue Mar 03, 2009 2:59 pm

Jarger, I Have a Trident 160 boiler. The same thing was happening to me when i started burning coal in Oct. Having said that, this is how i run the stove now. I fired it up somewhere in Nov. and it's been running ever since. Basically you have to shake down aggressively, so i open the ash door and leave it open for about 5 or 10 minutes to get the fire livened up. If i have a good fire i shake until there is a good orange glow over the entire ash pan also there will be some hot coals in there as well, if i don't have a good hot fire because it's been 14 - 15 hours since the last tending i'll throw on a thin layer of coals leave the ash door open and let that get well started then shake down. I then load it up to the top of the fire brick and mound it high in the middle. Now you got to leave the ash door open unitl the coal gets going good or in my case i wired in a timer switch in parallel with the relay that controls the ash door flapper. That way i don't have to worry about forgetting to close the ash door. I set the timer for about 10 to 15 minutes. I leave the two load door vents 1/2 turn opened from the fully closed position. No back puff worries that way. Thats pretty much it unless i forgot something. Don't forget, you got to get the ash out. Shake 50, 60 times if you have to, poke from under or above but, ya gotta get the ash out or the fire can't breath.

Good luck, hope this helps
Jeff
JB Sparks
 
Stove/Furnace Make: Harman - Chubby
Stove/Furnace Model: Harman: SF160 - Chubby Sr.

Re: Question about maintaining a fire

PostBy: Joe in NH On: Tue Mar 03, 2009 3:50 pm

Adding to the Harman boiler operating wisdom of my friend J.B, I have the smaller Harman SF260 and believe that it operates in the same manner as your SF360. You have a lot of boiler there. A barometric damper is essential especially in cold and windy weather. It sounds like you have a good chimney with plenty of draft. I keep the idle air control (covers the two holes) at about two thirds closed and the the draft flap at about 3/4 inch open at the bottom. You might need a little more air with both given the size of your boiler. I open the over fire draft spinners about one to two turns when getting a new load of coal burning. This keeps those little gas "pops" in the firebox to a minimum. I close them once there is plenty of blue flame.

I also found that ONLY shaking the grate will not remove enough ashes to maintain a long term fire. After shaking I also need to take my four foot long iron bar with a three inch right angle bend on the end and rake the ashes down through the fire from the top. The SF360 will probably require a longer bar. Pay particular attention to the corners and the edges of the firebox. This is done through the loading door. Ash build up could be the reason that your fire died after four days. Be sure to leave the clean out door open for a few minutes prior to working on the fire from the top so that you will have a good, strong fire. Keep the grates in the closed position while top raking the ashes so that a minimum amount of hot coal will fall into the ash pan.

My Harman arrived with one layer of firebrick laid in horizontally. That amounted to about five inches (?) of firebrick. You need to load the coal in your boiler to at least eight inches and higher would not be a problem. I put a second layer of firebrick in my Harman that was probably not necessary. I have read on this forum that firebrick is not necessary when the steel firebox wall is cooled by the water in the boiler. Anyway, mound the coal up and let those blue dancers fly.

Don't give up. I had been burning smaller coal stoves for over twenty years and learning a boiler was a whole new experience. There is some great coal burning experience on this forum so keep asking the questions and the answers will come. Joe
Joe in NH
 
Stove/Furnace Make: Harman
Stove/Furnace Model: Trident SF 260 Boiler

Re: Question about maintaining a fire

PostBy: Jaeger On: Tue Mar 03, 2009 8:44 pm

Guys thanks!!

Devil, I fill it to the top of the fire brick a full 10" from the grate to the top of the brick.

Freddy I do not have a barometric damper on the boiler.

JB and Joe, thanks for the insight on the SF boilers. From what I understand they 160, 260, 360 are identical except for the size. Thanks for the tips.

I'll check out the links Devil provided and see about adding a barometric damper.

Do you guys have any reservations with burning the bigger stove coal in the boiler?

I guess another mistake I've made is loading it like a wood stove a little bit at a time. Once I've got a good bed going it's ok to just load that puppy up and relax?

Thanks again!!...........Jaeger
Jaeger
 
Stove/Furnace Make: Harman
Stove/Furnace Model: Trident Boiler model SF360

Re: Question about maintaining a fire

PostBy: Razzler On: Tue Mar 03, 2009 9:59 pm

I can throw 40 or 50lb in on top of a good fire leave the ash door open for 20 minutes give or take 5 min's and it will be cooking nice close the ash door set the draft knob then let it go for 12 to 14 hours and it will still be glowing nice when i check it. ;)
Razzler
 
Stoker Coal Boiler: EFM DF520
Coal Size/Type: Buck

Re: Question about maintaining a fire

PostBy: titleist1 On: Tue Mar 03, 2009 10:15 pm

In addition to the baro, I would also recommend getting a manometer. There is a good thread on manometer installs in the Venting, plumbing, chimneys, controls..... area.
titleist1
 
Hot Air Coal Stoker Stove: Harman Mag Stoker (old style) one in basement, one in workshop
Hand Fed Coal Stove: Harman Mark III on standby for long power outages
Coal Size/Type: Rice/Anthracite; Nut/Anthracite

Re: Question about maintaining a fire

PostBy: Joe in NH On: Tue Mar 03, 2009 10:45 pm

Jaeger - I have used Blaschak nut coal almost exclusively in my SF260. I have recently been mixing in some pea coal left over from last year. I think that the size of the coal is not critical to the operation of a heater the size of the Trident series of boilers. Coal size might mean an adjustment in the idle air and draft flap in that the larger the coal the hotter it will burn. Your automatic draft control should pretty much compensate for the different sizes. Now that I know that you do not have a barometric damper, I think Freddie hit the nail on the head - your draft was out of control and your fire was burning out. I am surprised that your dump zone was not activated. I can not imagine running a boiler the size of the SF360 without a barometric damper. Please get one installed as soon as possible. Joe
Joe in NH
 
Stove/Furnace Make: Harman
Stove/Furnace Model: Trident SF 260 Boiler

Re: Question about maintaining a fire

PostBy: Jaeger On: Wed Mar 04, 2009 8:08 pm

Guys,

Thanks so much for all the advice.

My friend the HVAC guy is coming over Friday to toss a Barometric damper in the pipe, and I have a manometer from when I installed my radon pump.

I'll get them hooked up and give it a go Saturday AM.

I'll keep you guys up to speed with my situation, keep your fingers crossed and thanks again!!!..............Jaeger
Jaeger
 
Stove/Furnace Make: Harman
Stove/Furnace Model: Trident Boiler model SF360

Re: Question about maintaining a fire

PostBy: GaryFerg On: Thu Mar 05, 2009 11:10 am

Along the same lines i have a energy king hand fired boiler and have trouble running through coal it only lasts 8 hours and sometimes less and I seem to be using a lot of coal. 4 ton so far on a 2400 square foot house. I do have a baro damper and it is let as low as I cam get it, the boiler is in an out building so i am not to concerned about co. The damper really stays open all the ttime in other words full dampening. I circulate the water to my oil fired in the house and make domestic hot water as well as heat the house. Any suggestion? I wanted to get the Harmony but couldnt get one so i setteled for this thing which was a lot more money.
GaryFerg
 
Hand Fed Coal Boiler: Energy King boiler
Hand Fed Coal Stove: Harmon TLC 2000
Coal Size/Type: Nut
Other Heating: oil

Re: Question about maintaining a fire

PostBy: coaledsweat On: Thu Mar 05, 2009 11:33 am

GaryFerg wrote:Along the same lines i have a energy king hand fired boiler and have trouble running through coal it only lasts 8 hours and sometimes less and I seem to be using a lot of coal. 4 ton so far on a 2400 square foot house. Any suggestion?


My house is 2200' and a leaker, I've gone through about 4 tons so far this year so you aren't too far off (generally 5 tons per year). Try filling it a lot more to get longer burns, load the coal right up against the steel where it has water behind it. I run 4-6" above the bottom of the door in the center of the boiler, I stay shy of the ends where the steel is bare. The fire is healthier and I have less trouble with clinkers, it will go 16-20 hours if needed without losing it. Mine is a small (90K) boiler that I believe is similar to yours.
The first thing I would do is double check that damper for proper draft with a manometer or draft gauge. If it is always open, there is a good chance you need a bigger one. That may be where your coal is going... up the chimney.
coaledsweat
 
Stoker Coal Boiler: Axeman Anderson 260M
Coal Size/Type: Pea

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