eko-40 owners.

[bernard]

i have been burning for about 10 months now, eko-40, with 500 gallons of storage runs great no oil man. burning seasoned wood seems to gassify well gets up to temp and charges tank no problem. every once and a while the stove will backfire and puff smoke back through the fan. the primary is at 9mm the secondary at 3.5 turns out the fan opening obout 25% fan speed at 50%. Has anyone else had this problem? Maybe my air adjustments could be off? Is there a correct setting for a perfect burn? The wife would appreciate not being bothered to finish typing this pargraph. And of course no huffing and puffing! Thanks for the help.
Dave and "the wife"

 

[Nofossil]

If your wood is dry, you may need a smaller primary setting. On my EKO 25, I had to close it down to 5mm this year.

 

[stee6043]

What's your flue like? Good draft? I've never had any puffing back through the fan myself. I'll get it every once in a while if I'm stupid while loading wood mid-fire. But never with the system "on" and running on it's own...

 

[twofer]

This year I've begun to experience it myself and I believe it is because I working with better wood (that doesn't sound right, heh). What I've noticed is that if my I have too many small splits it tends to happen more. Lately I've been loading it with small splits (2-3" across) for the first quarter of wood and load the rest of it up with the larger splits (4-6" across). Seems to have helped although I'm not sure that's what the problem is or if it is affecting efficiency.

 

[Fred61]

This is my first season with my 500 gallon unpressurized storage and have been running my EKO 25 flat out unlike last year without storage. On some fires I have been experiencing a series of "explosions". Sounded sort of like when you run your tire into a curb and all the air escapes instantly. Yesterday I experienced this phenomenon and it continued to explode about once a minute. I was filling the basement with smoke since each explosion produced a fair amount of smoke out of every place on the boiler that you can imagine, with most emitting from the inducer fan. I had to do something because it was only a matter of time that I was going to hear from the little woman upstairs. Well to make a long story even longer, I found the problem and temporarily corrected it but I haven't yet figured out what set up the conditions to make it happen.
What I discovered was the nozzle area had a covering of small coals that were tight enough to restrict the flow and the unit would stop gassing for a few seconds and then ignite all at once over and over again. Now opening the door is something I didn't really want to do but I had to do something. I simply took the poker and moved the coals out of the nozzle area and I was back to regular gassing.
Why is it happening this year? A couple things have changed. First, I am using very dry wood which I had split down to a maximum of 4 to 5 inches in diameter to try to alleviate bridging per discussions on this forum last year and I have not been cleaning the ashes out of the top chamber which is forming a "funnel" allowing more coals to fall toward the nozzle. It could be one or both of these changes. Or perhaps something else I have not thought of.

 

[Medman]

Burning good wood here for the past two years, and I am still experiencing this. It occurs during idling or on fan start after idling, when the fire first gets a shot of air in the firebox. Also, draft does come into play. I have poor draft due to large trees around my shop and wind off of the lake, which causes downdraft. (Same problem with the woodstove in the house). If I am using an exhaust fan in the shop I have to remember to keep the window open, even with the fresh air duct I installed this year. If I don't, I can pull smoke through the fan inlet when the boiler is idling.

I have found the shop full of smoke more than once this year due to this puffing.

 

[Donl]

I get this too on occasions. In fact, last year I got a big one. It was so forceful it blew one of the secondary air pipes towards the front of the boiler. Enough to bend out the front green panel. I just reset the pipe with a hammer and all has been fine since. I think too much fine split dry wood may be the culprit.

Don

 

[Duetech]

Bernard, Nofossil has given a very valid point on air mix (too much O2 in the gasification chamber and poof) and I would look at that as soon as you look to see if the nozzle is obstructed or there is a lot of ash build up around the nozzle so you end up having a long funnel to the nozzle or if the chimney needs a cleaning. The primary air mix on my EKO40 is about 6mm.

Twofer, Too small of a split will allow the fire to come up into the gasification chamber as the smaller splits allow too much air space in the pile and when you get enough O2 in the upper chamber you will get secodary igniton and a poof.

Fred61, I took a 4' long 3/16" steel rod and made a 90* bend on one end and then 90* to that bend I put a slow curve in the rod, starting at the other end, and fashioned a tool that would reach up into the nozzle and clear or make holes in the small coals and ash that sometimes builds up in the nozzle. Of course I do that when the boiler is off. On days when I can attend the fire I burn a lower btu wood and mixing types of wood can add to the problem as well. Different woods will burn at different rates and generate coals at different speeds. The simpe cure for mixed woods is layering woods as to type and not haphazard placement. Then of course there is the air mix like Nofossil was suggesting.

Medman, There may still be too much air through your primary air mix and or a possiblity of carbon build up on your bypass damper preventing a complete seal. My boiler will idle for hours without puffing even with the purge cycling as per design. But it still does happen. That is usually when the nozzle gets semi obstruced and the gasses cannot escape via the draft or it is time to clean the fly ash out of the chimney T because the draft is restricted or there is above optimum wood moisture content in ONE (snicker snicker riiight!) of the pieces of wood in the boiler. There are chimney cap assemblies that help eliminate down draft problems but some of them can cause condensation to drip and that is a nuisance. Perhaps you could go to a longer chimney to give a more positive draft??? I was considering plumbing air specifically to the blower intake and Iwas wondering if that is what you did with your fresh air duct? Thanks for any info...

Just some of my observations.......

 

[Medman]

I never thought of the coals obstructing the nozzle, but it makes sense. I have Primary air at 6mm now - may reduce to 5mm at next cleaning.
Bypass damper is clean, as is flue beyond.

I have tested various chimney heights and cap assemblies with my woodstove. The results are that with near constant downdraft conditions like I have, a taller chimney just clogs at the top because of condensation of flue gasses. Venturi-type chimney caps are the best, but are very costly and require constant cleaning to keep operating correctly.
My local stove shop says that I live in the worst possible place - at the bottom of a tall hill on the prevailing wind side, next to the lake, surrounded by tall trees. No matter what way the wind blows, I get downdraft. So do all my neighbours, and I have recommended the venturi-type cap to many. I haven't got one on the boiler yet, due to cost. Maybe next year.

Air intake is just a 4" intake vent with insect screen through wall, then 4" insulated duct in a U shape to make a heat trap, then duct drops down under boiler. Cold air rises up around bottom of boiler when draft fan is running. Heat trap prevents cold air from spilling into shop when draft fan is not running. When I have the exhaust hood above boiler on, it creates an air curtain effect that pulls smoke up and out of the room. Combined with the draft inducer kit, I have much less smoke this year than last when loading.

 

[Jeff S]

I too have experienced this blow-back effect with my EKO 25 using very dry wood,nofossil shared earlier that he reduced his primary settings - was wondering if he would also share the settings of his secondaries and fan adjustments.

 

[Nofossil]

I too have experienced this blow-back effect with my EKO 25 using very dry wood,nofossil shared earlier that he reduced his primary settings - was wondering if he would also share the settings of his secondaries and fan adjustments.

He might.....

I'm running 5mm primary, 4.5 turns secondary, and about 3/4" at the wide end of the fan opening. I have the old controller so there are no adjustments there.

 

[bernard]

thanks for the input fellow pryos. i will check the draft with a meter if anything i might have too much i live on top of a ridge and the wind never stops. i did notice a lot of ash in the upper chamber maybe the fire is getting too far from the nozzle. maybe i should clean it out once and a while... and play with the adjustments. thanks again dave

 

[bernard]

i gave the boiler a good cleaning top and bottom. too much ash up top and way too much down the secondary chamber it was blocking the tubes in the rear of the boiler. closed the primary too about 5mm. 3 turns on the secondary and its humming along just fine. i guess we all need a good cleaning once and a while. thanks for the input. keep the fires burning. dave