# Is chugging, puffing etc... bad?



## mark123 (Nov 15, 2011)

I have a woodgun E-180 and have been trying to resolve the chugging puffing problem for a while now. AHS says to close the intake damper a bit but I feel like this will reduce my overall BTU output, is this the case? Anyway lately I have just been letting it chug as long as it wants, my intake is ducted from outside so no smoke leaks into my house when it is chugging. Will letting this continue cause any harm to the boiler or are these repeated explosions insignificant to the structural integrity of the boiler.


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## jebatty (Nov 15, 2011)

Bad? ... I can't answer your question directly. Is the chugging/puffing occurring during a normal burn or during the idle periods or start-up from idle? I'm familiar with a WG E500 that experienced such explosions during or on start-up from idle periods, not during burn periods, but very uncomfortable at best. Issue solved with added storage. Now the WG always purrs, never shuts down until the wood load has burned out.


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## mark123 (Nov 15, 2011)

If the wood is very dry and small such as 3" rounds and especially if I fill the firebox. Even yesterday I put in 4-5 6" spruce rounds that were 2-3 years old but were wet from being outside and it chugged for a while. AHS told me to only fill the firebox 1/3 full, isn't that defeating the purpose of having a large firebox. In another phone call they told me my wood was probably too dry, which is contrary to what most people try to acheive with their wood. Lately I have just been filling it and walking away until the next day and let it do it's thing. It is in the basement in a sealed room with ducted outside air so I cannot hear it and smoke does not enter the rest of the house.


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## jebatty (Nov 15, 2011)

I'm not familiar with the chugging problem you describe. This has not been experienced with the E500; maybe out of luck because perhaps the wood isn't as dry as yours is. I burn very dry wood in my Tarm and have not experienced this issue. I have read somewhere that spraying water on too dry of wood before loading is sometimes done. I agree that only loading 1/3 full is not the operation that I would expect. Others on this forum have mentioned issues with burning very dry, small splits, and fires that may get too hot. Hopefully someone else will have info that is helpful to you.


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## muncybob (Nov 15, 2011)

I have had the "chugging" during a burn. For me it seems to have been resolved by closing the air intake damper to about 75%. I would imagine that it may cut down on the btu output but it still meets my load needs. Experiment with the damper to find your sweet spot. I have had the "explosion" too but that normally only happens when it tries to restart when the stack temps are still around 300+.
As for loading, I will load to just over half full. With the smoke shield in the way I can't load anymore even if I wanted to. On the coldest of nights this still gives me around a 9 hour burn.... depending on the wood.


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## steam man (Nov 15, 2011)

Large oil/gas fired boilers will do that when you have excess air. I'd say cut it back. Also, stack heat loss is the greatest heat loss from your boiler due to excess air. If anything, it would be more efficient. The higher temp going up the stack with more air just means your pushing the heat up the stack. Without knowing how much excess air you have (O2 etc.) you never know for sure how much you have.


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## weiland13 (Nov 15, 2011)

Last night I was burning some dimensionsal lumber cutoffs from a home building buisness.  It was not treated lumber so back off of me.  That chugged a bit because I should have split the 2 x 12's in half.  Burning them at full size blocked off the bottom nozzle.  I had to re-position the wood so it was verticle in the box instead of horizontal.  I also closed the fan shutter more and it burned quietly and strong after that.


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## Gasifier (Nov 15, 2011)

I have had only one experience with puffing. No chugging. After reading a bit and talking about it with other Wood Gun owners, I closed my damper to about 60-70%. No problems since then. Good luck Mark.


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## mark123 (Nov 15, 2011)

The other thing I notice is that if I open the door it stops, isn't this a sign that it needs more air? Another option I could have ordered when I bought the woodgun was a belt driven fan instaed of the direct drive which is standard. Apparently this option is used when wood chips and very dry small pieces of lumber are going to be burnt. Would the belts just be a way of increasing the gearing to the fan to speed it up and thus move more air? Anyway I guess I will try closing the damper down for a few weeks and see how the output is.


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## WoodEnergy (Nov 15, 2011)

Most of my experiences with chugging and puffing weren't bad, but that was a long time ago in my college days...


:lol: 


I think the WoodGun uses a negative pressure firebox so you are getting pulses of fresh air "whooshing" into the primary firebox and causing mini-explosions of woodgas. Less primary air and more secondary air would probably help with extremely dry fuel, bit I don't recall if that's adjustable on the WG. Check the lower passages for black charcoal that has blasted its way back toward the ID fan. If no charcoal you are probably fine.

Incidentally, I'm having some major issues with "sneezing" on my Pro-Fab Empyre Elite. The Empyre uses a pressurized firebox and horizontal fire tubes (4 left, 4 right, directly off the secondary combustion chamber) which curve upward to vertical at the flue connection. After an extended bout of "sneezing", all 8 tubes are clogged with black charcoal, which makes for a very messy 2-hour tube cleaning.

Here on the Front Range of Colorado we mostly burn ponderosa pine that air dries to ~4%, so its pretty extreme conditions for a wood gasser.


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## mark123 (Nov 15, 2011)

AHS had been working on an add on to help with the chugging, it is basically a diverter made of 3 or 4" pipe that sends a portion of the incoming air down closer to the slots in the bottom, one problem is it takes up room in the firebox and has not completely solved the problem so I am not going to buy it. They explained to me that the heart of the problem is that the flame climbs too high into the pile of wood and this is not what you want. Closing the damper starves the top of the pile of air and then it cannot burn and the chugging stops.


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## Gasifier (Nov 15, 2011)

Most of my experiences with chugging and puffing werenâ€™t bad, but that was a long time ago in my college daysâ€¦

 :lol: Good one. Yes, and sometimes our Wood Guns have the Clinton problem of not inhaling enough.


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## wantstoburnwood (Nov 16, 2011)

Hey Mark . my econoburn chugs occasionally and only when i have small , dry wood . If the fire is really high in the firebox it definately makes a difference. (stay away from the waste oil)


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## Jesse-M (Nov 16, 2011)

The air fuel ratio is off, I've been thru this problem as well....although I have a completely different unit. In my case closing off half of my intake air has almost stopped it, and if it's windy I adjust the flu damper closed as well. Mostly due to reloads of fresh fuel, but it has happened in the middle of a burn to. I would not let it continue to chug......it's not good for the unit  ( IMO )


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## Fred61 (Nov 16, 2011)

I always looked at it as pre-ignition (pinging) like in an automobile. Gasses start their combustion before a sufficient amount of air is present then explodes when the pocket of air reaches it. The way to stop pinging in an auto is to change the timing or change the fuel. Since you don't have a means to change the timing on the boiler, you need to change the fuel. 
However,
I suppose playing with the air supply could change the "timing". There isn't much smoldering going on when your unit is puffing, in fact it's burning darn hot  so I wouldn't worry about reducing the air flow.


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## mark123 (Nov 16, 2011)

Using an IC engine as an analogy I would assume that closing off the damper too much would cause it to burn rich and carbon up and burning lean would keep things hot and clean. Iguess it is just a matter of finding the sweetspot. I wonder if somehow you could use and O2 sensor in the flue to control the intake damper and maintain a near perfect fuel/air ratio.


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## TCaldwell (Nov 17, 2011)

as described above chugging is due to the lack of sufficient combustion air, extingushing the flame, then a inrush of combustion air that ignites the volitale gasses. This is caused by mis metered primary and secondary air control. Realize that thees are batch fired boilers, typically with premetered p/s air percentages that try to maintain a clean burn within a varying o2 level. Lambda sensor equipted boilers will attempt to maintain a given setpoint throught the burn, retarding the burn at te start by reducing primary air and increasing secondary, middle of burn increasing primary and decreasing secondary, slight control changes and end alot of primary and no secondary in hopes to maintain setpoint. With a controlled burn there should be very little chugging.


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## Fred61 (Nov 17, 2011)

To my knowledge, Wood Gun doesn't have a means to provide secondary air. At least mine didn't. 
I think they compensate for it by allowing a high flow of primary air.


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