HELP with Harmon SF 260

KTM, I would set the S350 at 20* and the adjustable differential at 15*. I'd also set the A350 down to 170* because you will always get a 10* drift in water temp after the ash door damper closes. with the S350 set at 20* you won't be having the dump zone coming on so much and your first floor will stay closer to the thermostat setting.

You are correct in that the front of the fire box burns up first. I use a poker and rake the coals around the edges of the fire box and then use the shaker. Don't forget, short choppy strokes on the shaker so as not to dump the coal bed. Also when loading fill it to the top of the fire bricks and mound up the center. With a house as well insullated as your's, you should be getting 12 hour burns easily.

One other point, if you get a water temp drift more than 20* after the ash damper closes, close down the idle port just a touch more. 1/16" at a time. It gets pretty touchy when you get close to the right settings. The objective is to stop the temp. drift but still have enough air for long idle times. Check the ash door damper and make sure when it's closed it is flat against the square housing, if not you need to loosen the three 1/4-20 bolts and adjust it so it is against the housing on all four sides.

I would also set the baro at -.03 to .04., .05 will let the fire run a little to hot using up your coals. You should be using no more than 50# a day. If after you get the burn times up to twelve hours and you feel that your still using too much coal you could consider installing a fire box reducer available from Harman for you SF260. - Jeff

Bob,

My water heater is on 110. We have had no troubles with our hot water. You figure a hot tub is 104 and plenty hot. I've run it at 110 for 3 years because of the kids, we don't want to risk any chance of scalding. You figure your getting 140 degree water out of your faucet when you really only take a 100-105 degree shower. You use less heating the water to 110 and get a quicker recovery.

When I shake it (only 2-3 times a day) I use a long 3' pry bar and push down into the top of the coal to loosen it up. When I push down into the coal you can feel it get soft. I'll poke like 8-10 holes into the coal bed, close the top and bottom doors and shake away for about 10 good short 1-2" strokes. Then I check the ash pan to see if any of the orange embers are dropping. You can actually feel the soft stuff getting dumped when shaking. I can feel the hard stuff hit the grates because it gets harder to shake. That's a good indicator you've dumped all the ash. When they are I stop and open the top, and the bed has dropped a few inches. I stick the pry bar back in a spot or two and make sure that it's all hard stuff, top it off and close it up.

I think if your shaking it without breaking it up you get some of the soft stuff but it forms like a layer of dead ash space between the coal and the grates. I think that's what the guys here call "bridging?" By breaking it up I get rid of all the soft stuff and have hard coal resting on my grates when I'm done shaking. That layer of stuck together coal and ash could also be stopping your air flow choking it out.

Remember don't shake it too much I think that can cause problems too, not to mention the heat you loose opening the door. I like the old saying "play in the fire you'll pee the bed!"

Keep me posted and Good luck and don't give up. Remember a week ago I was dreading getting this thing fired up because I had the same exact experience you're having now.

Jaeger

Bob - You have gotten some great information already, but I just want to reemphasize a few points. I am in my second heating season with my SF260 and I can assure you that your coal boiler should do everything you want it to do. Both Jaeger and J.B (my good friend Jeff) have touched upon what I consider to be the single most important practice in successfully operating a Trident coal boiler - you must aggressively work to clear the ashes out of the firebox. I have found that if I am not able to maintain a consistently hot, active bed of coals then nothing I can do with the adjustments will make that much of a difference. As good as the Harman shaker system is, it will not by itself properly clear the ash build up.
My shake and fill routine goes something like this. I will shake the grate with the recommended short choppy strokes. This is to clear any ashes that have accumulated directly on the grates and I usually end up seeing a few red coals fall into the firebox. I will then open the clean out door so that the fire can get active. If the fire has been on a burn cycle (draft door open) then this might take only a minute. If the fire has been idling then it might take a bit more time. When the fire has become active and there are flames throughout the firebox, I then take my four foot "J" shaped poker and stir up the entire bed of coals. The objective is to sift all the ash that has accumulated through the coal bed to the bottom of the fire where they can shaken through the grates. I will work the front which is usually the area with the most ash to sift through and then move to the back paying particular attention to the corners where the ash build up tends to be the worst. I will work the poker down into the coals and move it along the top of the grate. You will feel the soft ash disappear as the coal bed settles. I will again leave the clean out door open until there are flames and then fill the firebox with coal. Another short shake where I will expect to see red coals falling and I am done. VERY IMPORTANT - open your door spinners at least a full turn when you have a fresh load of coal. The over fire air is necessary to clear the coal gas and eliminate any explosive buildup. Please don't ask how I know this.
Your SF260 came with the firebrick laid horizontally which gives you about a four and a half inch depth of firebrick. Many of the Trident owners on the forum have turned the firebrick vertical to provide a deeper firebrick bed. Turning the firebrick is a good summer project and is probably not something you need to be thinking about during the heating season. Anyway, regardless of the level of the firebrick, you can still fill the firebox as deep as you want with coal because you have the boiler water jacket behind the firebox wall. As I understand it from postings on this forum, the water will draw off the heat of the coal directly in contact with the steel wall and reduce the need for firebrick. Coal likes a deep bed and a deep bed will give you the extended burn you require. I would think that a depth of at least eight inches in the back and sloping down to the front should work for you. My SF260 is a bit over sized for my application so I am using the Harman firebox reducer which makes my firebox about 16 inches by 15 inches.
I have my A350 set at 180 degrees and usually have a high water temp of 185 - 190. I like the higher temp because I have more BTUs available when the system calls for heat and there is less chance of a crash should multiple zones activate. I have the Harman hot water coil installed so I cannot comment on using a water tank. Look to Jeff for this kind of information. I keep the draft door setting at wide open and the idle port set at 3/16 of an inch. Expect to use some coal. The SF260 is a fairly large unit and all those BTUs need to come from somewhere. I use between sixty to eighty pounds of nut coal per day depending on the outside temperature and my firebox with the reducer is only about 2/3 the size of yours. You also might want to consider using pea coal for longer burn times.
I do get carried away. Don't give up. Finding this forum is the best thing that could ever happen to a new coal burner. Actually it was this forum that gave me the courage to move from my little hand fired stove in the living room to the SF260 in the basement. A move that I have not regretted. Joe

Joe in NH thanks for the info. I have a question what size house are you trying to heat? Your comment about expect to use some coal is not what I wanted to hear. If I go from 3 ½ tons to 6 to 7 tons a year my wife will shoot me. Granted I am heating my hot water and the house is warmer but that is still a big jump in usage. Time will tell and I still may pull the plug on it if usage is to high.
The boiler seems to be working better since I have made some of the suggested changes. Today will be a good test being the first day back to work. Hopefully it is still going when I get home. Again thanks for all the help.
Bob

KTM,

I'm heating 4000 sq ft of living space + 2000 of unfinished basement. I have 4 tons of coal in my bin and don't expect to use it all by the end of season. I'm not sure but I'm only using those 4 buckets (5 gallons) of stove sized coal a day.

The experts could probably give you better ideas on your burn rate and all. I think you're using a firebox reducer which I guess would lessen your usage.

Hope it made it through the day for you..............Jaeger

I was just reading about these units on Harman's website out of curiousity .... but I was thinking if I were to buy one of these, it was a tossup between the 160 & 260 ... but the 160 would probably suffice in this drafty mess of a house. With that said, I think the 260 could be way oversized for a modern house with 2x6 construction. That might be the reason for the constant outfires -- prolonged idling. I'm thinking with the insulation the house has, this unit isn't even going to stretch it's legs, so to speak, until temps are down in the single digits.

What do you guys think?

Smitty, as an SF 160 owner and knowing the heat this unit will produce I would absolutly agree with you. Although my house is old with 2x4 balloon framing, I have had insulation blown in and have all the windows replaced with double pain units, I would say I have the house pretty tight. The 160 spends most of it's time in idle mode except when the temp gets down to 25* or less but even then I get 12 hour burn times easily. Jeff

JB Sparks wrote:I have had insulation blown in and have all the windows replaced with double pain units

Were they that much trouble to install? Freudian slip I'm sure.

Coalkirk, I guess I should have said Insulation blown in the walls and windows replaced with bouble pain window units. There did I catch the error?

I think coalkirk was playing on the spelling of the word pain vs pane.. double pane windows.. they are a PAIN to pay for. I know, I just bought 12 new Anderson double hung, double pane windows.. at about $500 each.

Greg L

Ha...Didn't catch that... obviously. I was always one of the first to sit down in school spelling bees.

In 1986 when I changed out all the windows in the house, I had a busted leg with a full leg cast and was hobbling around on crutches. I changed out one window a day...didn't have nothing else to do. Talk about a pain changing out the panes.

Thanks for the eagle eye.

Got home last night after a 10hr burn and all was well . Wife told me that between her and the kids there were five showers taken in a very short period of time and everyone had hot water. I still need to lower the temp on the hot water tank. So I waited from two more hours and went down and did the fire fixing routine and right before I went to bed I put a little more coal on. Got up this morning and again all is well . Today will be a better test seeing how temps have fallen into the low teens and not suppose to get much higher then that. Also winds blowing up to 35 mph. Wind chills below zero.
Jaeger So your heating almost 6000 sqft for a season on 4 tons of coal. If you are using 4 5 gal buckets a day and I will guess that a bucket is at least 20lbs ( I am going to weigh some buckets tonight). So using this weight that means in 3.5 months you will use up your 4 tons. Not sure were you live but maybe that is how long your burning season is.
Right now I am not using a fire box reducer, will have to look into one after I get things settled.
Smitty, I went with the 260 because if you look at Harmans spec,s you will see that the 160 is right on the edge of being able to heat my house. As far as prolonged idling this is a possibility but why wouldn’t the boiler be able to idle all day long as long as it has coal and enough air? This should be no different then a free standing stove. If it does a lot of idling then I guess in theory I should use less coal.

Thanks
Bob

Nice work! Glad to hear you are getting the hang of it. FYI, I think a 5 gallon pail of coal is 35-40 lbs; let us know what you get.

KTM250 wrote:Smitty, I went with the 260 because if you look at Harmans spec,s you will see that the 160 is right on the edge of being able to heat my house. As far as prolonged idling this is a possibility but why wouldn’t the boiler be able to idle all day long as long as it has coal and enough air? This should be no different then a free standing stove. If it does a lot of idling then I guess in theory I should use less coal.

I did notice that on their site & was thinking the same for my house ... one would be a little small & the other would be oversized ... I think I'd rather have too much than too little when it comes to heat.

I'm not all that familiar with stokers, but I thought that when they idle for prolonged periods, that ash can build up & cause an outfire? I just don't know having never owned one, or even seen one in operation, aside from videos on this forum. You seem to have above average insulation due to the 2x6 construction (do you have electric heat? That explains the extra insulation), so this unit seemed far above what you would need to heat the place ... at least to me. Don't know if that's a bad thing or not, but I thought it might explain the constant outfires. Maybe the idle air just needs fine tuning?

All that matters now is that your warm during the worst cold/wind spell.

Bob - I live in a cape style house located in northern New Hampshire with about 2000 sq ft of heated space. We have a high today of 4 degrees with a pretty strong wind and I expect to use at least two forty pound bags to heat the house and hot water. The Harman SF260 keeps the house as warm as we like and also heats our unfinished basement. Given the coal prices in northern NH, this boiler is not inexpensive to operate. However, it is worth it because I really enjoy the coal heat and tending the fire. I have a baro but do not have a manometer so my draft setting is a guesstimate. My coal consumption could probably be reduced somewhat with better draft management. Every heating situation is unique and now that it appears that you are getting a better idea of how to operate your Harman I expect that you will soon have a pretty good idea of your coal consumption.

As I mentioned previously, I am currently using the Harman firebox reducer for the SF260. I went through making the same decision as you (SF160 vrs. SF260) and chose the SF260 because I thought that it would be better to be oversized than undersized. Although I am now convinced that the SF160 would have more than met my heating needs, the SF260 with the firebox reducer works very well and I am more than satisfied with this stove.

On another note, I called the Harman Stove Company on their customer service line (800-664-3119) today to ask where the sidewall water jacket was located in relation to the bottom of the firebox on a Trident boiler. It took me two calls to get someone on the line but I thought that this was better than waiting on hold for the next available representative. Anyway, after waiting a few minutes while my question was researched, I was told that the water jacket begins just below the horizontal firebricks. This means that filling the boiler above the firebricks with coal would not be a problem. So fill her up. Get back if you have any additional questions. Joe