Need Help Burning Coal in a Harman SF 260

KTM250 wrote:EFO One more question. Is there any problem or concerns about what happens when the power goes out? With the original setup you would still have a draft going through the idle holes. With this setup you would have no air flow. So where is the coal gas going to go? Maybe I am looking at this wrong.
Thanks
Bob

It will idle the same as before. The air is being pulled through the combustion fan at idle. The blower plate is how you adjust your idle air. A bigger worry about a power outage is keeping the boiler from overheating. If you boiler is lower than your baseboard or radiators you should be able to open you flow checks or zone valves and let gravity do it's thing to keep the boiler from overheating. There is a way to pipe it so a valve opens when you lose power and your not there to manually open the valves.

EFO Sounds good. My boiler is in my basement and my zone valves are powered to close, so if I lose power all my valves will open. My only other thought on this is when the weather gets warmer and the boiler is not calling for heat will there be enough air flow through the fan to keep the fire going and also produce enough draft. Maybe you would have to adjust the air re stricter on the fan. This sounds like it would be worth a try. I should be able to makeup another flapper plate and switch back if I need to. Let me know how he makes out as the weather warms up.
Thanks
Bob

KTM250 wrote:EFO Sounds good. My boiler is in my basement and my zone valves are powered to close, so if I lose power all my valves will open. My only other thought on this is when the weather gets warmer and the boiler is not calling for heat will there be enough air flow through the fan to keep the fire going and also produce enough draft. Maybe you would have to adjust the air re stricter on the fan. This sounds like it would be worth a try. I should be able to makeup another flapper plate and switch back if I need to. Let me know how he makes out as the weather warms up.
Thanks
Bob

As long as you have chimney that will draw in warm weather you should be fine. You may have to close the blower plate a little in warm weather to keep the boiler from overheating. My friend fired his Sf260 early this year and it would idle great on a 60* day.

Thanks to Joe in NH.
That answer is exactly what I needed. I have been burning nut coal in a Stelrad (Austrian) boiler for 20 or so years. This year the cast iron snapped when I was refilling it after replacing a leaky drain valve. So I bought and installed a new Harman SF-260. I fired it yesterday and spent the day adjusting the controls. Had a beautiful fire all night, let it go until about ten AM. Looking good, then it just went out. So in an attempt to shake it down, the shaker seemed to jam so I had to keep opening the grates until I dumped all the coal into the pan. That was OK though as I just dumped the coal back into my bin. My old Stelrad had similar shaking grates but I never used them. The design was such that I could slide a rod on top of the grates from the front and that did the job. My thought was not to disturb the bed of coal. But now I see what needs to be done. It is now 60 out so I will wait until tonight to restart the fire. Thanks again. I thought my experience would carry me through the new boiler start-up. Well almost.

Well now really frustrated. The shaker grates getting stuck, the poking with the rod still don't seem to help. I can get a good fire going no trouble. When I add coal and or try to shake it down is when I have the problem. Running a new boiler should not be this hard. At this point I am thinking this is a wood boiler and not designed for coal. I can't imagine trying to burn pea or rice coal. I will contact my dealer on Monday. In the mean time I will keep trying.

The next time you have your firebox cleaned out, take a look at the grates.. you will see the fingers pointing at each other.. then work the shaking lever, note how the fingers move apart, leaving a big gap for a hard chunk of coal to get into and jam the grates..

I recommend to new Harman product owners to to the above 'inspection' of the grates. then using a piece chalk, or if it would work a few pieces of tape, and mark the maximum travel of the shaker bar on the side of the stove or in your case boiler. This will help you to not open the grates too wide when shaking down the ash, and causing a jam. It's a technique learned by all Harman hand fired owners..

A quick comment about shaking and coal.. If the coal is not being burnt so hot that it is fusing the ash into clinkers, [temps in the ash above 2700*], then the coal should be burning down to be just a powdery ash, like chunky oatmeal or granola cereal. IF the coal is good quality coal, with low ash content, and very little shale in it, this is what you will have, just gritty, powdery ash..
If the coal has a high ash content and has lots of unburnable shale in it, then you will have lots of frustration trying to shake this unburnable stuff through the grates.. The only way is grind this stuff up with repeated shaking with a heavy load of coal pressing down on the layer of ash, so the grates get to grind down the hard ashes.. sort of like putting more weight on a file when filing a piece of metal or wood, it cuts better with more weight applied..

When I had my 'Big Bertha' boiler running in handfired mode, I had lots of frustration with the grates I had installed in this firebox.. they didn't shake or rock, they slide back and forth, like a file trying to shave off the bottom of the ashes.. it didn't work well at all with most coal. The combination of chunks of ash staying behind after shaking, and the high fire temperatures I was running, created some spectacular clinkers.. the size of phone books..

What I finally had to do, was build a fresh fire each week, the first few days it burnt well., but as un-shakable [un grindable] ash accumulated, the fire got weaker, the air to the fire was being blocked by clinkers, and by the end of the week, the fire could not keep the boiler up to temp.. so I let the fire go out, and dug out the huge clinkers and started with a clean firebox.. Sometimes I was able to get under the big clinker on day 4 or 5, and pull it up the side of the firebox, leaving the fire mostly intact, and was able to go another week.. but this was rare..

Hope the above helps you climb your learning curve with your boiler.

Greg L

Greg Thanks. I started a new fire this morning and looked at the grates. I was even thinking of putting some sort of stops in but I like your idea of just marking the limits. I just shook the fire down and almost "vibrated" rather than shook the handle. It looked like it did a good job. I may have been burning too low a fire as well. I don't have klunkers but unburned coal. I opened the idle fire control all the way. I will continue to try different things until I get it right. This forum is a huge help. I still think this boiler is way too touchy. Should not be this hard to get it down. I had a Stelrad for 25 years so I thought this should be easy. On the Stelrad they had similar shaker grate system. It did not open up as much and never got stuck. On the other hand I ended up not using the shaker grates at all. The design was such that I could slide a rod under the fire and just on top of the grates. That is how I would shake it down. The light at the end of the tunnel is that people apparently figure out how to use the beast.

Thanks again. I will post updates.

Yep, the common description for Harman shaking is 'short choppy strokes'.. like you said, more just vibrating the ash down. You might be able to use a similar technique with steel bar in the harman,, but you will have to design the right shape, bent arm, angles etc, to make a scraper to work through the door and work over the top of the grates.. it might not be worth the time..

I'd definitely add coal first, adding weight to the coal bed, then shake down the ash.. Maybe this will help.. try everything.. I know there a folks that are happily using this make/model of boiler.. it's just a matter of figuring out the techniques..

Best of luck..
Greg L

OK I think I got it. I talked to Harman. Boy they really make it hard to talk to them. You have to go through your dealer first. That is not a bad thing but you would think a big company like that would have great customer service. I get the feeling they supply the product through the dealer then they take a hands off approach. Luckily my dealer (Phelps and Sons in Vernon CT) is great. Anyway, Harman told me to bank the fire up towards the back. I think that was the key. Ever since then it is going great. I am now fine tuning the Idle draft. Trying to keep the fire low and going when it is warm out. When I am sure I have this down, I will play with the boiler water set point temp. I am now keeping it at 180 or so. I am thinking I could change the set-point to a lower temp when it will be warm (40 or so). Then I thought Wow it would be nice to have the set-point controlled be the outside temp. That is thought for another day, or year.

Thanks to all. This board is a great help.

hi everyone,my name is Steve. Real happy to have found this discussion.I have been burning coal about 28 years. I was using a DeDietrich CF 120 6 section cast iron boiler. It cracked a few weeks ago and I'v nearly made up my mind to go to a Harman SF 260. Reading through the posts has answered some questions I had.One thing that bothers me is the automatic draft control.What happens if the controler has the primary air door open and the power goes out? Harman offers a non electric kit,is this a themostat and chain set up? That's how my old boiler was and it worked great. Also any pros and cons on the SF 260?