Keeping coal burning all day and night.

[Nor’easter]

Just read this thread thru & hopefully can shed some light on the subject, since have been burning a hand fed harman sf 160 boiler for quite some time. Now understand that both our boilers are similar, however all situations are different. You said you burnt wood last year with reasonable success. So even though it was milder, things worked OK. Yep coal is a different animal.

First thing I would do is get a poker & use it. Really sounds like with your V shaped firebox that you have some serious ash build up going on. Take that poker and rake it around the edges, then plunge it over the rest of it and give it a little wiggle. You will see the coal bed settle. Only do this after the fire is ramped up good by opening the ash door. Doing this with a sluggish fire will put it out. Also poke real good along the front, as that is where the bed is the least & you want to make sure that is as full as possible with fresh coal. Now when you shake you should clear the WHOLE coal bed, & not just the center. Ifn it happens to jamb up, stop , load up & shake it out on next reload. Load it deep as you safely can. A good 8 inch. Sounds to me that you are only using a part of the bed presently. how often the poker is needed, only time will tell. I use mine EVERY reload. Had a friend who had a Vogelzang furnace with the same box configuration. He would use a 4Ft poker & would look like he was mixing cement. Raking that thing to clear the ash.

Also the reason the front of your coal bed is burning out is because the secondary shutter on the load door is open too much. Had the same problem. Front would burn out... back wouldn't burn. Had to keep gradually closing the spinners till I got an even burn.

Now assuming that your baro is set properly, it sounds like that you need some sort of idle air. Mine is on the primary flap & is adjustable. The opening is almost equivalent to a dime. I use an IR gun & set the idle so that door temps maintain about 200deg.

If clearing the ash isn't enough, you might want to think about drilling a 3/8 hole in the plate on your ash door. You can always bolt a small plate to swivel enough to open or close that hole.

See how this works.

Jim

Thanks for the input, some good info here. I do have a poker that I use when the ash gets built up but I was just poking it up through the bottom. I’ll give your technique a try.

I’m glad you mentioned about having the blower door open too much. I was starting wonder about that because I closed it a bit a couple days ago and the coal seems to burn for ever without much ash build up. It seemed like I found the sweet spot!

Also I am using the whole bed. I just bank it higher in the middle and higher toward the back which is what others on here had suggested. It seems to work better. However, I am open to suggestions. And I make sure it’s as deep as I can safely get it.

Thanks again!

[OTR]

Hmmm, a bit late to the party, but I'll chime in with my experience. I run an OWB that can burn wood or coal, so my situation is a bit different than yours, but I suspect some of the things I've learned will still apply for you.

Tip #1: cut down the differential temp. When I burn wood, I usually set the differential at 10 degrees. This did not work well with coal. I found that setting the differential to 2 degrees helped immensely at keeping the fire healthy.

Tip #2: deeper coal bed. Looks like you've already discovered the benefits of this. Just always keep it stocked and don't allow the fire to burn to the point that there is white on top.

Tip #3: rice coal on top. I use nut coal, since rice will slip through my grates. I discovered that putting a somewhat thin layer of rice on top of the nut really seemed to help the burn quality - the coal bed burns much more evenly this way. Also, this makes tip #2 much easier to execute - say the bed is getting gray on top but there's still a ton of coal burning. I can just throw a shovelful or two of rice coal on top, as opposed to the bucket or two of nut coal it would take to get good top coverage.

Tip #4 (this one will be controversial): After the fire has been established for a day or two, I start doing daily clinker fishing with a long L-shaped rod I welded together, with a handle at the end. The reality is that no matter what I do, clinkers build up in the bottom, then start messing with the airflow - not to mention take up a surprising amount of space where coal should be. So, once a day, I fish out any clinkers. Please note, this may not be a good suggestion for your case - being that I'm in an OWB, my situation may be very different than yours.

I've had my fire going nonstop since November first. I can easily get 12+ hour burns without any attention paid to it, but if I am home, I tend to check on it every 3-4 hours or so, maybe throw a shovel of rice coal on top.

[Nor’easter]

Hmmm, a bit late to the party, but I'll chime in with my experience. I run an OWB that can burn wood or coal, so my situation is a bit different than yours, but I suspect some of the things I've learned will still apply for you.

Tip #1: cut down the differential temp. When I burn wood, I usually set the differential at 10 degrees. This did not work well with coal. I found that setting the differential to 2 degrees helped immensely at keeping the fire healthy.

Tip #2: deeper coal bed. Looks like you've already discovered the benefits of this. Just always keep it stocked and don't allow the fire to burn to the point that there is white on top.

Tip #3: rice coal on top. I use nut coal, since rice will slip through my grates. I discovered that putting a somewhat thin layer of rice on top of the nut really seemed to help the burn quality - the coal bed burns much more evenly this way. Also, this makes tip #2 much easier to execute - say the bed is getting gray on top but there's still a ton of coal burning. I can just throw a shovelful or two of rice coal on top, as opposed to the bucket or two of nut coal it would take to get good top coverage.

Tip #4 (this one will be controversial): After the fire has been established for a day or two, I start doing daily clinker fishing with a long L-shaped rod I welded together, with a handle at the end. The reality is that no matter what I do, clinkers build up in the bottom, then start messing with the airflow - not to mention take up a surprising amount of space where coal should be. So, once a day, I fish out any clinkers. Please note, this may not be a good suggestion for your case - being that I'm in an OWB, my situation may be very different than yours.

I've had my fire going nonstop since November first. I can easily get 12+ hour burns without any attention paid to it, but if I am home, I tend to check on it every 3-4 hours or so, maybe throw a shovel of rice coal on top.

Thank you! Some good suggestions here. I never thought of changing the differential temp I just always viewed that as only a safety measure so I will try that it makes sense it would make a difference. The other suggestions for the most part I am doing in some form or another but always willing to try different techniques or approaches.
I am finding more and more what seems to work better with keeping the fire going and keeping it hot and reducing the ash.

[coalder]

N, was wondering how you were making out. Hopefully by now you have figured just what works for you with regards to clearing the ash. Remember, you are looking for a fully illuminated ash pan after shaking, no shadows. And a very even burn across the top of the coal bed when heat is called for. Now if you don't have an ir gun... Get One!! When heat is called for, & the boiler has been running full bore for say 10 to 20 min you are looking for temps of 500 to 600* on the upper third of the load door. This in and of itself is the best barometer for how well your boiler is running. If everything coal bed wise looks good, & those temps can't be achieved you may need to adjust your baro in order to increase draft; there-by raising the temp of the boiler. I know the manual for your boiler says .04 WC; however mine says .06WC and if I set my draft for .04WC, my boiler would puke & die.

Just remember ya gotta look for those load door temps in order for everything else to work right.

Good luck & keep us posted.

Jim

[Lightning]

Tip #1: cut down the differential temp. When I burn wood, I usually set the differential at 10 degrees. This did not work well with coal. I found that setting the differential to 2 degrees helped immensely at keeping the fire healthy.

Ahhh.... I wanna try this with my Axeman.

[btarby15]

Hmmm, a bit late to the party, but I'll chime in with my experience. I run an OWB that can burn wood or coal, so my situation is a bit different than yours, but I suspect some of the things I've learned will still apply for you.

Tip #1: cut down the differential temp. When I burn wood, I usually set the differential at 10 degrees. This did not work well with coal. I found that setting the differential to 2 degrees helped immensely at keeping the fire healthy.

Tip #2: deeper coal bed. Looks like you've already discovered the benefits of this. Just always keep it stocked and don't allow the fire to burn to the point that there is white on top.

Tip #3: rice coal on top. I use nut coal, since rice will slip through my grates. I discovered that putting a somewhat thin layer of rice on top of the nut really seemed to help the burn quality - the coal bed burns much more evenly this way. Also, this makes tip #2 much easier to execute - say the bed is getting gray on top but there's still a ton of coal burning. I can just throw a shovelful or two of rice coal on top, as opposed to the bucket or two of nut coal it would take to get good top coverage.

Tip #4 (this one will be controversial): After the fire has been established for a day or two, I start doing daily clinker fishing with a long L-shaped rod I welded together, with a handle at the end. The reality is that no matter what I do, clinkers build up in the bottom, then start messing with the airflow - not to mention take up a surprising amount of space where coal should be. So, once a day, I fish out any clinkers. Please note, this may not be a good suggestion for your case - being that I'm in an OWB, my situation may be very different than yours.

I've had my fire going nonstop since November first. I can easily get 12+ hour burns without any attention paid to it, but if I am home, I tend to check on it every 3-4 hours or so, maybe throw a shovel of rice coal on top.

I too run an outdoor coal boiler, burned wood it in for the few two years, but made the switch to coal. Even though it's a coal boiler, I had to make some modifications to make it burn well. I agree with the temp differential. Mine was preset to 15 degrees, which was way too much. Once cooled down that much, it struggled to get it back up to temp. I'm still fiddling with it, but seems that anywhere from 2-5 has advantage. I've also fiddled with natural draft, using a magnet to keep the ash pan door cracked 1/16"-1/8". Blower shuts off when water is 180, natural draft tends to keep it going and raise it a few degrees more, and it prolongs the cool off period. Just have to be careful, I've cracked it too much and come out to a soft boil!

I burn stove size coal, I like the tip of throwing a smaller size on top, definitely going to try that. I feel like when the blower does kick on, it can blow too much heat up the chimney stack, maybe smaller size on top will help that.