Looking to Buy a Harmon SF-260

I'm thinking about purchasing a Harman SF260 to heat my house. I currently have a Weil Mclain oil boiler running at 100K btu. I have 4 zones, about to add a fifth. I use my boiler for DHW and plan on continuing that practice by adding on the DHW coil to the harmon.

I know they are a pain and need to be fed regularly. I'm not to worried about that, I currently have a wood insert that I feed 4+ times a day, also I work from home so I'm always home.

My house is about 1850 sq/ft. I'm finishing off my basement so that will add another 350 sq/ft.

I'm worried that the 260 is to much for my needs, but I'm also afraid that the 160 won't be enough (we are thinking about building an addition in the next couple years, possibly up to 800 sq/ft). So I would rather get to big than to small. I'm going to lean on a friend who does heating to see what he thinks, but he doesn't know much about coal boilers just heating with boilers in general.

I am also toying with the idea of running my boiler year round. Is there a way to control/limit the heat for the summer time? I know you can purchase a firebox reducer but I'm not sure how good they are and how well they actually work. I'm hoping you guys can help me out with that one, with your personal experiences.

If the reducers work, I may just run with the reducer all the time if the 260 is to big for my current needs.

I've just really decided to go with a coal boiler, was thinking about a stoker stove but that just isn't going to work the way I need it to. I'm about to start to research install issues with hand fired boilers. I'm read some postings about dump zones, something I need to better understand.

Well I've rambled on long enough. Thank you in advance for your great insight!

What about a stoker boiler? Or do you want the wood option with the sf260?

binger552, I'm running a SF160 boiler in parallel with my oil boiler, heating 1800 sqft., 3 finished floors. The 160 handles it easily including the zero degree weather we have lately. I use nut size coal, but experimented with some pea size in the real cold weather, but went back to the nut size. I'll save the pea size for warmer weather.
As to the dump zone, you need to have some place to dump the water if the boiler water gets to hot, such as when you have a fresh load of coal, you can get an of overshoot in temp. Usually that happens sometimes after reloading and shake down. What I did for a dump zone was to tie in a relay that will bring on all zones at once to bring the water temp. down, Dump zone only runs about 2 or 3 minutes and then the boiler temp. settles out.
Harman is a good boiler, the only thing I don't like about it is the grate area is bigger than the ash pan so on shake down some of the ash falls outside the pan. To deal with that, when it's time to take the ash out I put the pan on the floor tight up against the boiler and use a hoe to rake out the ash still in the ash area. I keep a shop vac with a plaster dust filter bag close by the boiler and anytime i'm dealing with the ash I just keep the vac going to suck up the dust and then clean up the area when I've finished dealing with the ash and reload. It's easier to keep everything clean as you go rather than waiting till you have a big mess.

Hope this helps in your decision
JB

I'm not getting a stoker because I like the idea of going between wood and coal. I also like the fact that it costs about 2500 less for the manual boiler. Seeing I have lots of wood on hand and I can get pea and larger coal bulk and cheaper than rice coal (by about $50-60 a ton). I live about 30 minutes south west of Albany NY on I88. Currently rice is about 300 a ton and pea or nut is about 240.

I work from home full time so I'm always home anyways. I currently heat my house with a wood insert and I feed that thing about 5 times a day, at least. That keeps the first floor at about 70*. My basement is currently not heated. We keep the third floor zone set at 52*.

As for a set up. What's the advantage of a parallel vs in series? I'm thinking of putting my boilers in series, seems easier to plumb.

I like the idea of dumping to all zones. I also have a 115 gallon water storage tank attached to solar panels that I can dump to. I would just need to plumb a loop between the drain and relief valve and throw a heat exchanger or something in the middle to dump extra heat.

How about box reducers? Has anyone used the one sold by Harmon? I was reading a post about a guy running the 250 who said the reducer was worthless because it wasn't even big enough to fit the width of the box, left about 2" on each side.

Anyone have one for the *60 series of boilers?

Thanks for the help!

I have a Harman SF 260 and currently am using the Harman firebox reducer and hot water coil. I was somewhat surprised that the reducer is so complex (a bar to brace the firebrick, little feet to ride on the grate, etc) and well made. It fits the firebox perfectly and does not appear to change the burning characteristics of the boiler. I cannot remember the exact width dimension but I think it is about 7.5 inches. This reduces the 23-inch length of the firebox to about 16.5 inches and allows you to burn the boiler at a little over 70%. It is straining a bit tonight with the temperature at minus 15 and still falling. I suspected when I ordered it that the SF 260 was probably oversized for my needs but have always dreamed of adding and heating that hot tub on our three-season porch. It sounds as though you will grow into the SF 260 as you pursue your construction plans. It does a good job of burning both pea and nut coal. I tried testing it with some wood last fall during set up and created quite a bit of creosol. This probably had more to do with the warm ambient temp and my initial nervousness about keeping a low temperature in the boiler than with the unit itself. I plan to try wood again in the spring. I agree with J.B. that the ash collection design is a joke. It is a simple, well built boiler that works well for me. Joe

Joe in NH wrote:It is straining a bit tonight with the temperature at minus 15 and still falling.

Good morning Joe,

This is chance for me to learn a little something on the boiler, Can you tell me what the difference was in your fire when you say "it strained a Bit" at the low temps. I tried burning pea size during the last cold snap and thought it was working a little harder to maintain 180* water temp. even had clinkers for the first time since I've been running it (since Oct.). Went back to nut size.

Binger552,

I like the idea of putting the two boilers in parallel for a couple of reasons.
1. keeps the oil fired boiler at the same temp. all the time so the system doesn't care where the water is coming from, it runs just like one boiler only the oil boiler never comes on.
2. If the coal boiler goes out and i'm not here the oil boiler would come on and the wife doesn't have to do anything like turning switches or valves.
3. To add any additional loops you just have to put in extra tees in the supply and return lines. Don't need to use the boiler drain or the PRV valve for anything.
I have a relay operated by an extra aquastat on the coal boiler that electrically locks out the oil boiler so it can't come on unless the coal boiler water temp. drops below 120* (which would mean the coal boiler has gone out). This relay will also shut off the the circulator that runs between the two boilers so that when the coal boiler is off the oil boiler just heats the water in the oil boiler and not the water in the coal boiler.
It seems to me that if the boilers are in series, when a zone calls for heat the circulators have to push all the cooler water in the oil boiler thru the system making the system less efficient. Keep in mind that the coal boiler is a lot slower making up hot water than the oil boiler.

I would like to hear from others for their opinions on the differences between series and parallel hook ups.

J.B. – Happy Birthday, even though I think I am a day late. You were certainly up early on this Sunday morning. What I meant by “straining a bit” is that my fire was struggling to keep up with the heating needs of the house at that temperature (-15). I also keep my water temperature at 180 degrees and last night every time the water temperature would approach that level a circulator or two would kick on and drop it by 10 to 20 degrees. The fire in the 260 was strong (bright orange with many blue dancers). I had even turned down the heat in my basement clock shop and increased the draft flap opening by a half a turn. I gage the draft flap opening by a mark on the adjusting bolt. It is now set at about a 3/8-inch opening at the bottom of the flap. I am still working on the relationship between the amount of draft available to the fire, better controlling water temperature fluctuations, burn time and coal consumption. I guess the question is – if you increase the draft and with a hotter fire decrease the water temperature recovery time which will increase the amount of time that the boiler is in idle mode, will the burn time and coal consumption increase, decrease or remain the same? Now that’s a confusing question. I think I know what I am trying to ask; I am just not doing a good job of asking it. It looks like I will need to do some experimentation and record keeping. My problem is that if the fire appears to be going well and the system is balanced, I don’t want to mess with it even though the result might be an improvement.

I am primarily using nut coal with a little pea (left over from the Efel) for starting and fire recovery. Actually, my nut coal supply is getting low and I will probably be using the pea coal sooner than later. Joe

Joe,
I judge how hard the boiler is working by the stack temp. When the flapper aquastat calls for heat I have always allowed the flapper to open all the way, never thought about reducing the amount it could open. However when the water temp is low and it is trying to recover I've seen the stack temp get up to 300* and the fire is realy cranking, normally it runs around 130*. I suppose that is when I should try and limit how far I let the flapper open. I put an override switch on the syncro motor so I can change the setting without waiting for it to deactivate by the aquastat.

Let me know how you make out with the flapper setting and burn rate, that is interesting.

Yeah, I was up early, the back TELLS me when to get up.

My birthday is Feb.7th but I had to get all this media-care stuff done so it can be activated Feb.1st. Nice to get a break in the insurance premiums, now if the wife will only hurry up and get to 65 i'll realy save some $$$.

I tried the pea size during the cold snap, but went back to the nut size(more Heat). I'm going to need another ton before spring. Probably get Kimmals again, it's been burning good. Jeff

How much are these Harman handfired boilers new ? Does anyone have a ballpark figure?

Salemcoal wrote:How much are these Harman handfired boilers new ? Does anyone have a ballpark figure?

I found a sf-260 in June for a friend of mine.I had it shipped from a dealer in Ohio,could not find one around here. I think he paid around 3000 for it not including shipping or tax. He loves his.

Paid 2800 for my Harman SR-160 not including shipping and tax.

Joe in NH wrote:I have a Harman SF 260 and currently am using the Harman firebox reducer and hot water coil. burn the boiler at a little over 70%. It is straining a bit tonight with the temperature at minus 15 and still falling

Joe, I was just wondering why you are using the reducer now in the dead of winter with lows at -15? I would think it would be better to use the full fire box now, and use the reducer in the fall and spring when the temp's are higher.

Jeff AKA J.B.– Wow...draft damper wide open? I can only imagine what that must be like. No wonder you talk about four dump zones, overshoots and reducing the size of your firebox. I do not have a thermometer on the stack (I have a tendency to get a little crazy with too much data) so I have no way of comparing stack temp but 300 degrees sounds a little hot to me. I was thinking this morning that I might be too conservative with my draft opening and was considering increasing it a little to decrease my recovery time. Although our Harman Tridents are different sized models, I think my reduced firebox is probably about the same number of square inches as your full size firebox. I have added a layer of firebrick and fill my coal to a depth on the side of at least 8 inches and then mound in the middle. Even at my 3/8-inch draft opening, I feel that I am burning at a fairly hot temperature and I will occasionally get a golf ball size clinker. All that and I still worry about making it through twelve hours. You run your Harman with a coal depth of 4 inches on the side, draft wide open, and yet have no problem going twelve to fourteen hours. This is not fair.

Case in point. I did my usual short shake and top off last night at about 9:00 PM. Slept late this morning and finally got to the Harman at about 8:30 AM. After almost 12 hours at about minus 20 degrees, I found a fire that was still active but had definitely had a hard night. There was a lot of ash in the front and back and the water temp was about 130 degrees. Shook it down, dug the ashes out and loaded it with a forty-pound bag of nut coal. The blue dancers appeared after several minutes but it took the rest of the morning for the water temperature to reach 180 degrees. Granted, there were numerous calls for heat and hot water through the morning, but I still felt that it was a slow recovery. The other way to look at it – the house was warm the water was hot, so who cares how long the recovery to 180 degrees took. I think it is time to start tweaking things.

Here’s the deal. I will start to increase my draft opening and you will start to decrease yours. I would bet that you find that your boiler operates better at 2/3 to 1/2 less of the draft you are currently using. I am probably too conservative with my draft. This is probably a result of large coal stoves in the living room. At the same time, I consider the draft opening on the Harman to be a concession to the wood burning side and too large for coal. Let me know what you think. Joe

Razzler - I am using the reducer because I have this tendency to think that bigger is better and managed to talk myself into a boiler that is larger than I needed. I suspect that the number of square inches in the firebox using the reducer is approximately the size of a SF160, the smaller boiler that I should have purchased. Live and learn. Joe