smoke from gasser

[maineDIY]

Wondering if you guru's would weigh in on this topic. Last season which was my first, it seemed that my stove would gassify without smoke output nearly as soon as it started, especially if some live coals or even cold charcoal was placed over the slots between the upper and lower chamber when starting a new fire. This year with dryer( more seasoned)wood it seems that it takes forever to get the output from the stack to be clear. The wood if anything is drier. When strirred up and the inevetible bridging is reduced and glowing wood is pushed down nearer to the slots, then the effluent clears up--- but that is only possible much later in the burn and it requires my attention. Any ideas? It is a 60 kw vigas with Lambda. It seems to be "gassifying" right away but the air/fuel mixture must not be exactly right in that unburned fuel (smoke) is going up the chimney. Is there a way to fix this? I fear neighbors will be complaining about the smoke if I don't figure this out soon. Any suggestions appreciated.
GG

 

[maple1]

Mine is slow to start most times and spits out some smoke while getting up to speed - takes a while to get the chimney & refractory hot and a good draft established as I have no fan let alone any lamdba action. I've found that if I leave the wood chamber door open a crack (just pushed in against the latch) until things get heated up & the fire gets good & established, it improves things quite a bit. So maybe you need more air? Can you see movement in your air adjusting mechanism during the burn to tell if the lambda things are working or doing anything?

 

[maineDIY]

Mine is slow to start most times and spits out some smoke while getting up to speed - takes a while to get the chimney & refractory hot and a good draft established as I have no fan let alone any lamdba action. I've found that if I leave the wood chamber door open a crack (just pushed in against the latch) until things get heated up & the fire gets good & established, it improves things quite a bit. So maybe you need more air? Can you see movement in your air adjusting mechanism during the burn to tell if the lambda things are working or doing anything?

Well the electronic controller tells what the setting is supposed to be but I but can't actually see it. I could take off a cover to actually see if it's working if that is what is advised here.

 

[JP11]

Well the electronic controller tells what the setting is supposed to be but I but can't actually see it. I could take off a cover to actually see if it's working if that is what is advised here.

I don't really have a set method yet. I can't decide if I just load and smack the button.. Or if I leave the bypass open, but have the boiler "on" or If I should let the wood "catch" with just the inducer on, and the door open a crack.

Seems to get running, sometimes faster, sometimes slower. I never seem to do the same thing twice. Guess I should write down what I do..and how fast stack temp comes up.

EDIT>. you can see how much air it's getting. The "servo" number on the controller. Its usually 100% open and 100% fan when getting going.

JP

 

[maple1]

For starters, I would give it a good cleaning if you haven't already, then take a cover off to watch the air adjusters actually working or see what they are doing through a burn or physically see how far open they are during startup. Could it be that one is hung up for whatever reason on a partially closed setting?

 

[Clarkbug]

My first thought would have been that the drier wood needs different settings than the wetter stuff that you had last year. I had to adjust mine from burning some nice dry pine to my less dry hardwood. Before I did that, the pine would still smoke on me until there was a nice hot coal bed going.

I would say that you should make sure your controls are varying your air settings as you burn. Unless there is something else at work. Have you scrubbed your tubes yet this season? Or really cleaned everything out? Just wondering if you have some soot or ash plugging up a passageway in the boiler somewhere...

 

[maineDIY]

I don't really have a set method yet. I can't decide if I just load and smack the button.. Or if I leave the bypass open, but have the boiler "on" or If I should let the wood "catch" with just the inducer on, and the door open a crack.

Seems to get running, sometimes faster, sometimes slower. I never seem to do the same thing twice. Guess I should write down what I do..and how fast stack temp comes up.

EDIT>. you can see how much air it's getting. The "servo" number on the controller. Its usually 100% open and 100% fan when getting going.

JP

Well we're not talking the moments just after starting. We're talking an hour later when stack temps are up, wood is well started, and putting out good output. I expect it to be smoky when cold and just starting up although it would be nice if it wouldn't do it then either. I see that there is a sticky for adjusting air/fuel for an EKO on this forum. Does the lambda controller ever come out of adjustment or is that not something that one needs to worry about? Another thing that occured to me is that perhaps with a large load of wood there is bound to be some moisture present in all of that even if below the advised 20% moisture content. Shouldn't that just come off as steam depending on conditions? Would that not appear as clear at the stack with condensation to visable moisture some distance above it when it cools with rapid dissipation of the flume with no residual afterwards? That is not what is occuring. It is smoky right at the stack even with high two hundred to low three hundred degree stack temps. Certainly it should be invisable if it is steam at that temp. Please advise.

 

[maineDIY]

My first thought would have been that the drier wood needs different settings than the wetter stuff that you had last year. I had to adjust mine from burning some nice dry pine to my less dry hardwood. Before I did that, the pine would still smoke on me until there was a nice hot coal bed going.

I would say that you should make sure your controls are varying your air settings as you burn. Unless there is something else at work. Have you scrubbed your tubes yet this season? Or really cleaned everything out? Just wondering if you have some soot or ash plugging up a passageway in the boiler somewhere...

Yup--scrubbed out tubes with a brush on a drill as well as with the device that came with the stove (a long rod with a round piece of steel on the end of it slightly smaller than the diameter of the tubes). Everything seems OK in that regard. Should one remove the refractory slots to see if the secondary air tubes are partially blocked or is there some other passageway that should be checked?

 

[mikefrommaine]

I'd take a look at the air servo motors and make sure they are actually where the computer thinks they are. Could be one is hung up or not working.

 

[mikefrommaine]

I'd also check the o2 sensor. Make sure it's not fouled up. Your dealer should be able to the output voltage when it's operating correctly. Probably somewhere around .5 volts when running, but Im just guessing.

 

[Fred61]

I doubt wood moisture would cause this assuming it is somewhere +- 20%. Perhaps if you were into a section in your wood pile with wood that has thick bark, like butternut you could get excessive smoke. It's more likely in the combustion air, whether it be from adjustments or restrictions.

 

[maple1]

Yup--scrubbed out tubes with a brush on a drill as well as with the device that came with the stove (a long rod with a round piece of steel on the end of it slightly smaller than the diameter of the tubes). Everything seems OK in that regard. Should one remove the refractory slots to see if the secondary air tubes are partially blocked or is there some other passageway that should be checked?

Maybe clean well wherever & however the manual says cleaning is required? I think dirty tubes (heat exchange tubes?) like the ones that you cleaned out would affect heat transfer more than burning efficiency - whereas dirty intake air passages like secondary tubes would moreso lead to smoke. Dirtyness or something clogged should be the easiest & first thing to rule out - then check your air regulating thingies to see what they're doing or that they're doing something.

EDIT: Your description of smoking in the middle of the burn but not the start has me wondering if your air regulation is stuck wide open, and not cutting it back in the middle of the burn.

 

[JP11]

I'd also check the o2 sensor. Make sure it's not fouled up. Your dealer should be able to the output voltage when it's operating correctly. Probably somewhere around .5 volts when running, but Im just guessing.

Yup.. good advice here. clean the o2 sensor probe. And there's a part in the manual that tells you how to verify that the air intake shutter is at the position that the controller THINKS it's at.

JP

 

[heaterman]

More than likely you are not getting enough air to properly combust the amount of available fuel being burned. Smaller splits can do this because they expose more surface area to the flame. Drier wood can create the condition also because the wood is capable of burning faster not having to evaporate as much water.
Simple way to test is to load a smaller volume of fuel in the boiler and see if it clears up. Even with Lambda control you still have to regulate the air/fuel mix by introducing the "right" amount of fuel to the flame. Once the control calls for max blower speed (assuming the O2 sensor and the shutter, or blower as the case may be) it will still burn dirty if there is more fuel present than the amount of air can properly deal with.

 

[Robby]

Maybe!
I have the same unit, new this year. From day one it worked perfectly. A couple of weeks back it became slower to start gassification. That got worse and worse.

When cleaning I took off the front panel (has two fans and servo motor on it). The rear of this panel is the plate that turns to cover/uncover the holes to regulate air. It is attached to shaft with a small screw in the center, through plate to servo motor. On the back side it is spot welded to the shaft. On mine the spot welding was defective. There was penatration on the plate, but no penatration on shaft at all. All that was holding shaft was the screw and the plate was slowly slipping on the shaft. Called Mark at AHONA (permission to weld), spot welded with mig. Reinstalled, works just like it did on day one and has since.

Takes longer to tell what happened than to fix. I did not know where to set when reinstalling. CAlled Mark again, it's simple.

 

[flyingcow]

Also, why not call Mark AHONA? I'm sure he could help you the best. Plus it's his equipment, he'll make sure it's working correctly.

 

[maineDIY]

Also, why not call Mark AHONA? I'm sure he could help you the best. Plus it's his equipment, he'll make sure it's working correctly.

Great forum! I've got several ideas on where to look now. Thanks all for taking the time to try to help. Best holiday wishes!

 

[JP11]

Also, why not call Mark AHONA? I'm sure he could help you the best. Plus it's his equipment, he'll make sure it's working correctly.

I for one am glad that he didn't. There's not a lot to check out on these things.... but I'm glad that I learned a few new things today.



JP