Coal Gas Build up Causing Explosions

Hi all new here. We have an Axeman Anderson coal stoker. Had it for 18 years, had an older model prior to that. Never much problems until this year. this year it keeps building up coal gas. The basement started stinking, hubby had for the first time ever put a cover over the barrel coal bin. I complained about the smell, he took it off. Smell seemed to go away. Daughter home one day heard a loud noise called her dad, hubby came home and looked at the furnance, had a small explosion, and blew off the pipe. Had the chimmney cleaned. no problems there. Tonight had three small explosions that rocked the floor. Sounded like a car hit the house. Pipe is off, minimal damage to the furnance. Thankfully hubby is a professional carpenter, and he hoards coal furnace parts when he sees them. He replaced a funnel thingy and some other tubey thingy. Any ideas on why we are suddenly getting coal gas build up and gas explosions. Not sure where to look, but hubby hasn't done anything other than the lid, to the furnance this year.

Thanks for any advice.

Nervous in PA

SBarto wrote:Hi all new here. We have an Axeman Anderson coal stoker. Had it for 18 years, had an older model prior to that. Never much problems until this year. this year it keeps building up coal gas. The basement started stinking, hubby had for the first time ever put a cover over the barrel coal bin. I complained about the smell, he took it off. Smell seemed to go away. Daughter home one day heard a loud noise called her dad, hubby came home and looked at the furnance, had a small explosion, and blew off the pipe. Had the chimmney cleaned. no problems there. Tonight had three small explosions that rocked the floor. Sounded like a car hit the house. Pipe is off, minimal damage to the furnance. Thankfully hubby is a professional carpenter, and he hoards coal furnace parts when he sees them. He replaced a funnel thingy and some other tubey thingy. Any ideas on why we are suddenly getting coal gas build up and gas explosions. Not sure where to look, but hubby hasn't done anything other than the lid, to the furnance this year.

Thanks for any advice.

Nervous in PA

not sure where you get coal but your either burning buckwheat (the size smaller then pea) or superior breaker pea which is smaller then the others. this is most likly the case and if you got it from the same supplier there a good chance they either sold buckwheat or switch who they got it from and the pea is from superior...... BTW goto the boiler section and to the AA library and read the (bureau of mines report a lot of good info)....

one more thing if the anthrastat is the orginal it may be out of calibration making the ash bed more compact which could case the POP.

Thanks for such a quick response. Hubby, still dirty from working on the furnance says yes to both, new dealer we just bought from this year. Our older guy stopped delivering this year. Also still original antrostat. He also says he's been getting big "clinkers" this year, big chunks of coal stuck together, not had that problem previously. We use pea. Do you think it's raking too much or not enough?

Really appreciate all your help.

I just sent you a PM

Often the inspection port door is not swinging free from the boiler far enough, make sure you have at least 1/2" gap when the fan is not running. Can you tell us when the 'puff-back' is occuring?? is it after the boiler shuts down after a burn, or is it when the fan first starts during a burn cycle??

The Clinkers are an indication of a coal with less ash and plenty of iron that fuses with the heat of burning. Usually more ashing will move the clinkers out, off the grate faster.

I'm going to move this to the stoker/boiler/furnace forum for better exposure for your questions..

Greg L.

.

The inspection door is ok. the explosions (shook the house) occurred when the circulartor kicked on.

Today, everything seems fine so far. We've been checking it continuesly and husband stayed in the house all day to keep an eye on it. He had more minor repairs to make to it.

We really appreciate all of the help from you folks.

[quote="SBarto"]The inspection door is ok. the explosions (shook the house) occurred when the circulartor kicked on.

quote]

another question what was the water temp and pressure.... it's possiable that your expansion tank is low on air which if the water was over 200 going out and the water coming in was cool your system pressure dropped below 12psi and the water went to steam in your heat emitters..... do you have cast iron rads, if so the above will shake the house I know been there. but talking with your husband I know your cover was blown off maybe you have two problems maybe not.....