EKO 40 secondary air passages may be plugged

[hayrack]

I am on my second year with my EKO 40 super. I burn good dry seasoned wood and have had little trouble until this week. My theory is that my secondary air passages are plugged. I always burn full out with little or no idling due to having a 1000 gallon propane tank for storage.

This week after starting my fires and filling with my load of wood the minute I close my damper it all goes down hill. It acts like there is no place for the smoke to go and it will not gasify. I shut it down last night and this morning I pulled the plate off the top of the heat exchanger tubes. I thought they would be plugged or have some build up, but there was nothing plugged there.

My next thought is the secondaries are plugged in the refractory. If I remember correctly there is suppose to be a hole in each side of the nozzle to inject secondary air. I see no holes in the nozzle sides. When it cools down some more I will try finding the holes with a screwdiver or drill bit. Has anyone experienced this problem I am having

 

[taxidermist]

Check to see if your flap on your fan is opening up. Someone here had the flapper pin work out and the door was not opening when the fan turned on. To check your secondaries you can take the cover off and shine a light down the tubes and look in the lower chamber to see if you can see light from the holes.


Rob

 

[Duetech]

Do you have the Super model EKO40 or the older 40? I have the Super with the tube cleaning handle on the left side.
I had problems somewhat like you mention but that was from some plugged exchanger tubes where the trubolator blades had come loose. The only way your secondary nozzles ports could be plugged is through cold fires and smoke(no gasification) and creosote build up as the temps in the nozzle would burn off any build up. Is your unit in an unheated building? (cold wood will draw condensation even if it is the best mc wood to be had) Another thing you might check is the primary air ports that blow into the primary chamber located at the front top of the primary chamber. I have had considerable build up at these ports. Air coming in to the primary is potentially cooler than the primary chamber even though it gets heated to a degree before it enters the primary chamber and could throw the mix levels off.

There have been a couple reports of the secondary air adjustments creeping closed or partially pluged and that would create the scenario that you mention. You can access the secondary tube opening under the front panel where the blower is located. In some of the 60's there have been a few reports that the tubes themselves have rotated (due to thermal expansion and retraction from the on/off "feed the strorage" operational routine and/or the tubes not welded in place very well) but I don't recall any of the 40's reporting that condition.

With the boiler off you can take a hanger wire with about a 3/4" 90* bend at one end and try to carefully locate the secondary air outlets in the nozzle from the secondary chamber to see if they are plugged. There are two on each side in my model. Orlan was supposedly fitting models subsequent to my model with smaller but more air outlet ports in the nozzle. Once again because of the operating temperatures at the nozzle I really don't think that the outlet ports are plugged.

Since the draft works well enough before you close the damper it would seem the chimney is working correctly but it might do well to inspect that as well. Keep us posted please... Cave2k

 

[hayrack]

I have the front panel off and everything looks good and clean. I ran it last year without the door flapper for the fan, and I thought it may be stuck but it looks fine. I did shine a flashlight in the secondary tubes and I dont see any light in the nozzle. Should the holes be one on each side of the nozzle?

 

[hayrack]

Chimney and stovepipe are clean as a whistle also. I started at the chimney and have worked my way back to the nozzle. This may be the culprit. I need to let the refractory cool a little more before I investigate further.

 

[Dave T]

The picture i've attached shows my secondary inlet tube has a full weld, as CAVE2 stated some EKOs were only tackwelded around this pipe which is fine, but some broke allowing the steel inlet tube to turn misaligning the nozzles and tube air holes.

 

[Duetech]

On my 40 there are two holes on each side of the nozzle spaced about 2" or so in from each end of the nozzle slot.

 

[hayrack]

Thanks for the info and pictures everyone. I just got back in the house and am going back to the basement to check the holes in the nozzle. I see no obvious holes like I remember when it was new, and I have shined a flashlight through the tubes with no light coming to the nozzle or lower chamber. Time to get some wire and fish the holes out.

 

[woodsmaster]

Not sure how the eko is set up ,but on my biomass if you take the cover with the fan off and remove the adjusting plates you have about 5 holes on each side that go to the firebox. I clean these and the primary one every couple weeks. creasote tries to plug them even though there is no creasote on the exchanger tubes.

 

[hayrack]

I Have been burning again for about 12 hrs. with no problems. The only thing different I have done is remove the flapper door for the fan. I think it may have been cathing. My secondaries were not plugged at all. I ran last year without the flapper with no problems, so I guess I will leave it out. It rarely goes into idle mode anyway, so the flapper is not that big of a deal for me.

Thanks everyone for the tips.

 

[Duetech]

That is good to hear. Sometimes the smallest things create such large disturbances. One note of interest about the flapper though is that it is there to protect the fan/blower and you in case of "flash-back" which can occur in idle or similar circumstances when there are enough gasses and heat and O2 to cause ignition. It might do well to look at the cause of the "sticking" and see if it can be fixed. (just a thought)

 

[hayrack]

Thanks Cave2k. I probably will put it back in, I just had to leave it out for a while to verify this was my problem