EKO External Primary Air Controller

Here are some pic's for you of the EKO External Primary Air Controller I made. For some reason the pics did not display in order. The first pic you see is of the pieces/parts that are hidden under the blower sheet metal except for the part of the control shaft.

The second pic is the outside of the boiler with the control handle/indicator (minus the primary air slider mm position indicator).

The third and fourth are pics of the internal control assembly in the fully open and fully closed positions.

The fifth is of the control bar and control bar slider clip with the boiler primary air slider plate on the side with the cut out tab for the slider clip control bar bent down & out of the way.

The sixth is of the control bar and control bar slider clip as connected to the boiler primary air slider plate.

the seventh and last pic is of the assembly under the boiler blower sheet metal cover.

I was not aware the 60's primary air was up so high on the boiler. But now I do and I really don't know about the older 40's as I never saw an EKO boiler until 06.
Any how.........

The mm increments are easy to figure because the opening for the primary air inlets are 7/8" or about 21 mm. The only glitch is the primary sliders open 1/8" beyond fully open so add another 2 mm +/-.5mm. Place a 2" piece of masking tape on the face of the boiler sheet metal where the control/indicator is to track the full sweep of the control/indicator arm and you have a mm incremental indicator. Sorry for the carbon deposits in the pic's it's just the evidence of poor air/fuel mix and 2 years + of no storage burning. And you are right for 6.5k you would think the important parts would be there. Thanks for the input...Merry Christmas

Yes mine also enters low and goes up the inside and stops about an inch below the ceiling of the gassification/loading chamber. One of my future projects is to mount a slatted fence that hooks into the outlets to act as a smoke shield for loading as I intend to put the boiler into a shed with the storage tank which is in the planning stages. I never had this many projects burning oil. What do you suppose is the reason for that?

How far above the blowers are your primary air adjusters at? Do you think a controller would work on it?

Hi Tony,
Adjustments are quick. Until I put the controller in I was having trouble with my boiler keeping up with demand (single digits above and below zero and 30-40 mph winds) because (I thought) I was set up for summer/cooler time. There was a blue flame and I was getting a decent length burn but the hard cold conditions forced me to radically change my settings. Being able to set my primaries open to close in seconds alerted me to a problem I had been unaware of. My blower had been giving me problems by over producing air and my blower setting was very low but even so I did not know my secondary setting was too high putting too much air into the mix. They were too many turns out and with primaries set low I could see the secondary air blowing holes in my flame resulting in cold air going into the secondary combustion chamber and not igniting the primary gasses. To make up for too cool of an output from the boiler I had had to turn up the blower out put to maximum (which put more unburned fuel into the mix that was able to ignite before exiting the secondary chamber) to get the boiler to heat up. The boiler heated up nicely but I started consuming wood much faster going from a 9 1/2 to 10 hour burn to 6 1/2 to 7 hour burn in high cold winds. It's breezy and cold again with a new storm but now my blower settings are closer to where they were before that last bad one came through and my boiler is heating nicely. Once I realized my secondaries were out of whack and adjusted them I was able to cut back on my blower settings and get back closer to the more economical higher output settings I had been seeing just two weeks ago. Basically any adjustment I have to make is in the blower setting to adjust output now. My mix ratio is the last thing I have to tinker with even though I am now able to adjust to things in seconds that used to take hours of try this and try that. I can't disregard moisture in wood but adjust to it a lot faster and more accurately now. I could make kits, better looking than mine, but I would need to know some measurements and each kit will have to be tweaked to each persons boiler as there is a modification that needs to be done to the primary air sliders on their boiler and they will have to drill the hole in the right place where the control/indicator lever protrudes through the boiler blower mounted sheet metal (face plate).

Thanks Eric. Yes I think you are right. The design could/should work on the 60 and if the 18, 25 and 80 designs are exemplary of the EKO line design then it is possible that this primary air control could be adapted to them as well. My only concern is where the blowers are placed and if they would force an awkward positioning of the control. From the pictures I have seen of the 60 it would be an easy fit.

barnartist said:

Curious, I am not following what some are saying that the primaries are higher. Mine are all the way at the top.

Looks like a nice job Cave. How long did it take you to put it all together? Time well spent im sure....

Click to expand...

Part of two days in frigid cold weather but that includes some time at the hardware store but I think that it was time well spent as I found some things at the hardware store I didn't expect to find (lol).

Do a search on posts by Dean Zook. He has done some mods on this.

I have the older controller as well and have had some issues with the blower output on my boiler (I know you have been to the "Hyper active blower" post). I can shut my blower shutter completely closed and still have enough forced air to cause my boiler to work though not very well. Whether the blower is drawing air from the cabinetry where it is mounted I do not know but to have that much air flow with the shutter completely closed leads me to believe the fan housing and cabinetry and mount all need to be sealed in order to expect any real viability towards air supply and air pressure control. The new controller with speed variability seems the best approach and it seems EKO thought it an issue worth addressing. Theoretically your approach should work and will work but it requires strict control of air flow. Let us know how things work out if you pursue it>

Eric Johnson said:

I'm a little confused as usual. I took my blower mount plate off today to set the primary air adjusters, and the MINIMUM setting is about 20 mm. The 60 (mine at least) has two big vents to the right and left of the respective air control sliders. They don't go any farther than 20 mm when fully "closed." I notice that Cave's 40 seems to be quite a bit different. I mean, I have about a 1.5 x 1" opening on each side. Is yours like that, Cave?

I guess my question is: what the heck are you measuring to get a "primary setting" of 9 or 10 mm?

Click to expand...

Hi Eric,
Hopefully I understand you and will explain with my interpretation of your question. The 40 I have and the 60 TacoSteelerMan varies in placement of the primary air sliders but the construction basics are the same. If you are getting such wide settings I believe it is because your plates are either turned around or the slot that the retaining bolt goes through does not extend far enough. On the sliding plate there is an ear (a 90 degree bend) that sticks up about 3/16-5/16". This part of the slider should be towards the center of the boiler. The flat part goes to the outside. If your slider plate will not close to factory spec's with this orientation then you either have wrong or defective parts or EKO needs to write a new manual.

The slot was punched in the wrong spot or was just too short on the left slider plate on my 40. I had to extend the slot so it would fully close the slider plate and I could get equilibrium with the adjuster I was trying to build. As it was it would only close to about 8mm on the left side and about 5mm on the right side. There was a weld bead at the top of both slider plates that prevented the plates from closing completely. I adjusted the slider plate rather than trimming the weld bead. Hopefull your plates have just been turned around. Not having parts for comparison I believe the slider plates for the 40 and 60 are identical but that is a long distance guestimate without hard data. The opening to the primary air channel on my 40 is 7/8" wide (about 21mm) and the height is about 1.5". Photo 7 in my opening post shows the controller mounted to the front of my boiler with the slider plates fully closed and except for an intended design limitation your sliders should be able to move that far.

My tuned settings are: fan shutter 1/2" open. Primary air 6mm and secondary air at an average 1 3/4 turns.

In my case I only have one blower but if I had two I would try that in a heart beat. It is quite probable that you would have to reset your mix but I think you would probably get a more efficient burn. For test purposes just unplug the second blower at the controller and see how that works. There is a back draft damper on all of the blower setups I have seen on EKO's (but I have not seen very many).

My 40 settings are: blower shutter @ 1/2" open, primary @6mm and secondary @ 2 turns (lt) and 1 1/2 turns (rt) or 1 3/4 turns avg. My flame is very blue toned and I now adjust boiler output by blower settings alone. That said I still cannot open my blower all the way up with out cooling down my boiler temps.