I Just Had My First Ever Out-Fire in the AHS S-130 Coal Gun

And I just re-fired it a few minutes ago. No out-fires since October of 2011 until now. Could it be the Coal Contractors Mammoth coal?

A very hard coal with low volatile content will be more prone to outfires.

The first restart effort failed also. Got it going on the second restart though. With a steady load on it the water has risen from 114 degrees to 146 degrees in the past hour and the stack is finally good and hot now. Draft is at 0.03". It was at 0.01" when she lost the fire.

Not more than 10 minutes later update: 162 degrees and rising very fast now. Still under a steady load of hot water running into the basement laundry tub.

Update #2, another ~10 minutes. At 182 degrees and the fan (which is set for 180 degrees) has shut off. Seems to be all good again for now. I've turned off the load. Will restore power to the ash grate motor in another hour.

Over time your fire most likely got very high and very thin...perfect outfire conditions for coal such as Rob described.
The intermittent firing for low load DHW doesn't allow that type coal to accelerate easily and livening up and staying lit easily and the fire gets thinner and thinner.

With a coal such as this you may find your fire going back and doing an outfire again as the fire eventually after some days builds high and thin all over again.
You might consider washing the car(s) once a week with HOT water to keep the fire happy.

Larry, do you see a lot of unburnt coal in the ash pan also?
How long has it been since you started burning the CC Mammoth coal?

McGiever wrote:Over time your fire most likely got very high and very thin...perfect outfire conditions for coal such as Rob described.
The intermittent firing for low load DHW doesn't allow that type coal to accelerate easily and livening up and staying lit easily and the fire gets thinner and thinner.

With a coal such as this you may find your fire going back and doing an outfire again as the fire eventually after some days builds high and thin all over again.

Larry, do you see a lot of unburnt coal in the ash pan also?
How long has it been since you started burning the CC Mammoth coal?

I've been seeing a fair amount of partially burned coal for at least a month now.

My plan was to use Blaschak for the summer and Coal Contractors for the winter, but when it came to filling 2 of my 3 bin compartments with CC they did not hold it all, so the rest of the CC (what was estimated at 600 to 700 lbs.) went in on top of my remaining Blaschak in the 3rd compartment.

Funniest thing is that just this morning I noticed that my basement dump zone loop was running and the boiler was at an unusually high 215 degrees. Hitting the dump temperature limit hasn't happened for a good while now. It came down to 185 and the dump zone valve shut off as did the circ pump. Then not more than 12 hours later I found it running constantly, dropping completely raw coal into the ash bucket, and sitting at about 110 degrees water temp.

A proper temperature snap switch mounted a couple feet up near or on the boiler's hot water supply pipe could sense the outfire's temperature drop and lock out the supply voltage to to the grate motor and there by avoid emptying the raw coal from the entire hopper or bin.

This has got me thinking about a repeat cycle timer again.

Update: The fire is still going and all seems well.

I now have a second theory of the origins on my outfire. Could it have been from bridging in the gravity feed tube between the hopper and the fire pot? I've noticed occasional large chunks of coal well beyond the size of pea, and ranging from nut to perhaps stove randomly mixed in with the pea, along with plenty of random wood chunks. Any combination of these could have jammed up the feed tube and allowed the fire below to run out of fuel. What leads me to this speculation is that the fire in the boiler must have been out for some time for the water temp to fall to 110 degrees, and the boiler was found by me to be running and dropping raw coal into the ash tub, but not that much coal had accumulated in the ash bucket at the time I discovered the outfire. It seems to me that if the boiler was ashing endlessly for sufficient hours for the temp to fall to 110 degrees, the entire 250 lbs. of coal in the hopper should have fallen into and overflowed the ash tub, but only about 40- 50 lbs. of unburned coal did so when I discovered the problem. My new thought here is that a bridge formed and then at some juncture after the fire had been out for a few hours the "bridge" collapsed from the combined vibration of the fan and the ashing motors and the raw coal was freed to fall into a fire pot that was completely out, and then into the ash tub below through the never ending ashing.

Any thoughts as to this being a reason for the outfire, as opposed to the brand of coal being the culprit?

Is the coal damp?

Rob R. wrote:Is the coal damp?

No, it's dry as can be.

Your bridging theory is as good as any.

I have run range coal, a mix of nut and pea, with zero problems in my Axeman. Straight nut will not run to the pickup end of the auger due to its angle. Stove will jack you up. I would assume the same with your hopper fed.

The clean out of the raw coal that dropped into the ash bucket would/should of revealed the truth of the bigger coal and wood pieces theory. That would of been easy to see with the smaller amount of raw coal that had dropped.

McGiever wrote:The clean out of the raw coal that dropped into the ash bucket would/should of revealed the truth of the bigger coal and wood pieces theory. That would of been easy to see with the smaller amount of raw coal that had dropped.

Very good point! That ends my new theory, as all of the raw coal that passed into the ash tub looked pretty normal in size.

But then again: I've seen solids of small size (like granulated sugar for example) jam up and shut off the flow in food funnels, so perhaps under just the right conditions even regular size coal can bridge and jam up the flow?