KA6 Coking up in the Grates

Burning Millard and a little bit of Blaschak that's in my bin. I keep having my ash/coal bed coke up then not push off and then it stacks up and pushes coal over the sides. ... why?

If my reference to coking up doesn't make sense. .... what it's doing is burning into a solid clump and then won't push off the grate. It's hit and miss when it does it but usually in extreme cold when it's running longer.

Coal a little wet/damp? Friction on grate? The carpet on my Kaa-2 is more flat than your Ka-6. I don't have any problem. Dry wet/damp coal. Maybe sand grates. Any wax, or any other residue on grates from starting fire? Maybe try Buck size coal. I burn buck.

Your getting what I call clinker cakes. When your running your unit hard and burning a coal with a lower ash fusion rate, the ash will actually fuse together from the heat into a solid cake. This usually happens with coal that has a higher iron content or what is referred to as red ash coal. The fix is to mix in some buck or back off the air so it doesn't burn quite so hot. The long term fix is to blend in some white ash coal or coal that is lower in iron content.

This is not due to anything your doing and you don't have a problem with your Keystoker. It's the nature of the beast with higher iron content ash that is burned HOT in this cold weather. When the weather warms up a tad and it's not running so hard it will more than likely go away on its own.

Rev. Larry
New Beginning Church
Ashland Pa.

Ill bet if you mix in some wood pellets that will work also

I'm needing to get coal this weekend. I've been burning Mallard (Harmony) and I had tried Blaschak which I hated.....I drive from Central PA so I can go pretty much anywhere. Any suggestions? It never did this with the old Harmony coal.

Best to call ahead for who will have your coal...stockpiles are maybe low at breakers cause dealers are replentishing their stockpiles and breakers can't operate in these temps.

As w/ all heating fuels, supplies are dwindling.

That's what had me worried. ....I just want good coal. Mallard does ok until it's below 10 then it seems to cake up.

Remember, someone said to try some Buck and/or back off the air a little.
It's not all the coals fault.

I'm not sure how much to back the air down. My draft is having perfect. I'm picking up buck from a local guy. .... he sells Blaschak but I'll give it a try. Will I need to make any major feed our air adjustments with the change?

No, nothing major. Just do your usual manometer tweaks for draft after a 1/2 hr. steady run.
Then adjust the feed to proper position near end of grate.

Blaschaks usually has a higher fusion temp so you shouldn't see anymore "clinker cookies".

So I'm giving some buckwheat a try. Cleaned out all the rice and got it burning with buck and adjusted my air and damper to get my draft right after I had a normal coal bed and it's coking up again. When I cleaned the rice out I cleaned the whole boiler out do nothing is on the grates. What gives?

If your clinker cakes didn't go away with switching to the buck then you need to back off the air flow a bit and cool the fire down. I always had clinkers when I ran the UAE original. Your coal may just have a higher iron content. If you can get to the Keystone Anthracite site on Route 54 in Girardville Pa. Their coal has a lower iron content and I don't get clinker cakes anymore since I started using their coal.

What you got to lose right? Give it a try. Always remember, mileage may vary based on individual usage and performance.

Rev. Larry
New Beginning Church
Ashland Pa.

How much ash is on the end of your grate at full load?

Air will go through the buck easily, turn it down until the fire stops just before the last set if air holes on the grates. (Do this when the stoker has been running hard for about 30 minutes)

Which air are you referring to? The fan that runs all the time or the flapper on the bottom?