Fix for Eko RK-2001U controller flicker / flashing / blinking / E2 code

I thought I'd start a new discussion for repairs to these controllers, as the information already on the site was embedded in other posts. All thanks to Medman in this post:
http://www.hearth.com/talk/threads/eko-40-silicon-door-seals-and-the-new-refractory-brick.88005/
I was able to find my problem.

I just fired up an Eko 40 I bought used and found it had problems with the controller. The digits for the temp display would flicker and occasionaly flash higher random temps as it was warming up, and as I got into the mid 100's it would throw an E 2 error code ( meaning over temp condition ). The boiler was no where near 195* but the circuitry also 'saw' the high number derived from the temp probe. In addition, when the temp did reach my pump launch temp, it lit up the light on the front of the controller, but I was getting no power to my circ pump. I suspect the faulty capacitor wasn't providing enough power to engage the relay that runs the pump. I've seen posts where guys got seemingly random overheats and wonder if this fail to trigger the relay is the root of the problem.

The controller mounting may be the root cause of the problem - I suspect that the 3"x3" hole in the front bonnet where the wires come thru acts as a chimney and ducts hot air into that unvented metal 'teepee' and it occasionally hits close to 200* up there, which would be the death knell for an electolytic cap ( and eventually other components ). After I get my system debugged I'll check that with my Raytek IR gun and report back.

Rather than tossing $200 at a new controller, I tried a $4 capacitor changeout and it works fantastic now. Radio Shack carried a 2200uf 35v cap in their stores ( you could also sub a pair of 1000's plus a 220 wired in parallel if no 2200's in stock ). The size of the new cap is about 4X the old, so I just soldered in a few inches of 24ga jumper wire, black taped up the exposed leads on the new cap and tucked it inside the controller housing. Making those leads 6" long would have allowed for an even better spot to place the new cap.


In my data quest I also found a $1 part that should be able to replace the stock $45 temp probe. I'll start a new thread on that.

Interesting thought on the cause of the problem. I just checked the controller housing on my biomass. It's vented on both sides. I don't recall anyone with a biomass reporting a controller failure even though we have the same controller. So maybe eko owners should vent their controller?

I can't believe this thread. I was just going to start one about my temp gauge acting up all winter. It flickers from temps ranging as much as 20 degrees. It changes 2 or 3 times per second to make it worse. I can work around it but drives me nuts. It might screw up my fan cause it goes from fan to rest 100 times before staying on rest. Even worse, sometimes the pump goes on and off several times per second and might ruin the pump to boot. I heard from my dealer I need a thermistor. I didn't ask the price but I'm sure this is cheaper. Can ya show me where this capacitor is located. I imagine it is behind the controller. I think I can find a capacitor at radio shack too. Thanks. ihookem.,

ihookem,

Open up the controller ( 2 screws on case ) and look at my pictures and it will be very obvious which cap I'm talking about. It's right beneath the fuse holder which is the bright red object you see on the top edge of the second photo.

I'm guessing when your dealer is talking 'thermistor' he is referring to the temp sensor ( which is in effect a PTC thermistor ). I can't imagine many dealers are recommending you go after an internal part like this. Who is your dealer - I'm 50 miles north of you but didn't realize there was anyone close by.

Just when I thought I was the only EKO owner in all S.E. Wisconsin. My dealer is Ahona from New York. Does anyone look at you like ya suddenly started speaking Hebrew when ya explain how an EKO is a gassifier and how it works? No one has gassifiers around here.

Thanks for bringing this up again! My repair of this problem is still working well. It is a quick and easy fix (if you can solder) to the flickering display.

Ryan

Over the summer I had the same issue,since my EKO was still under warranty I called Zenon from New Horizons and he swapped me out with a another controller,he also mentioned that the capacitor had a tendency to dry out.Chances are next time I have this problem my warranty will be expired,but now I know which capacitor to replace.Thanks for the post 700Renegade.

Thank you for this post. I forgot about the fix for it and my biomass has started acting up. Off to Radio Shack I go today.

How old is your boiler? I think the warranty is 100% for five years.

It is 3 years old, but I can't take a chance of it messing up as I have no backup heat right now. Also this is only a temp fix. I am thinking about using my NFCS to control the boiler instead as then I would have more control over it.

I wonder if that is why my controller started having problems as the housing isn't vented.

I have had nothing but excellent and accurate advice from Mark at AHONA. Did you speak with him on the phone about the problem? He gave me a larger capacitor when I bought and picked up mine from him. The cap (mounted near the fans, not the controller) is for fan starting. You may have a bad sensor.

Good luck.

I talked with Mark on the phone in October. He said a thermistor?? Anyway, it sounds just like the same problem. I might call him again to see if it's under warranty.

To clarify, the thermistor and a capacitor are two competely different things.

The controller uses a temperature probe which is strapped to the top of the tank under the insulation. That probe functions because of a PTC thermistor contained in it's tip. In their wisdom, whomever designed the controller set it up to work with a fairly hard to source thermistor to measure the temp. Regardless, for $45 you can order an OEM replacement. For the brave tinkerer, I think I found a $1 part which "may" work as a replacement. when I get time I'll start a new post titled "RK-2001U temperature probe replacement" or simmilar.

From the description of ihookem's problem, I'd suspect the issue is the capacitor internal to the RK controller, not the temp probe. I could be wrong. If the $4 cap doesn't help, I'd look to the temp probe next. If your controller or temp probe are warrantied, that is fine, but you have to consider the time lost to mailing the controller if it's mid-season.

A fan start capacitor is an entirely unrelated issue......

http://en.wikipedia.org/wiki/Capacitor_plague

Stumbled across this just now - is this the root cause?

This is a timely post. I just had my 3rd controller fail in 4 months on my Biomass 60. Original one lasted just over 2 seasons and failed in September when I started it up for the season. New Horizon Corp has replaced them each time they fail but during the burning season this is not much fun. I believe the heat is what is killing them. My Biomass 60 was purchased in 2010 and I do not have any cooling vents in the hood where the controller sits. The last one I actually left sitting outside the hood to see if it would help but it did not. If someone has pictures of how their Biomass is vented I would like to see some. I have thought about drilling some vent holes in mine.

My control would click and flash last year. I also would get an E code, can't remember the numeral after however. I just tightened the wires a bit more than typical and have not had a problem since. The wires were secure but for some reason they needed to be a bit over tightened.

2011 model. Has two vents on each side.

Thanks for the picture that helps. I'm going to add some kind of venting to mine and maybe a small fan if I can find a good way to power it.

Like VTHeatGeek, I too have been through 4 controllers in two months, and bought a new one as a spare. The symptoms are very much the same - temperature indicator goes nuts, and ultimately goes blank and the unit just "clicks" repeatedly until power is removed. The problem is duplicated if you gently touch the front controller.

The scary part is that my first controller failed in this mode but left the fan on 100% with a newly filled boiler. The result was a bunch of steam, pressure relief valves spewing steam, and a big mess. Fortunately I was home and got the situation under control in 20 minutes but if we had been asleep or away the result could have been very different.

*** NOTE: I DO NOT ENDORSE, ENCOURAGE, OR RECOMMEND OTHERS OPENING OR TAMPERING WITH THEIR CONTROLLER ***
If you have the experience or desire to do so, you are proceeding at your own risk.

Being in the computer field for 30 years, four controllers failing in 2 months screams manufacturer's defect of some form. Being under warranty, I hadn't opened them up to find out the cause. However, the problem happened again yesterday so I swapped out the controller with the new one I purchased from New Horizons with the last warranty exchange. I setup a test lab with a 40 watt lightbulb for the "fan". Test results showed the unit clicked repeatedly, no temperature was displayed on the front, and the fan was "on".

Taking the unit apart revealed the defect that is so simple it defies logic why the manufacturer hasn't fixed it (or designed it that way to begin with). The temperature board connects to another on the bottom of the unit (pin connector labeled J1 in an above post) which offered no resistance when detaching the two. Further tests revealed that putting a flat rubber support under this connector covered by electrical tape then reseating the board resulted in a fully functional controller.

My theory is that the vibration causes the two boards to begin to separate and ultimately fail due to a poor connection. I am still concerned that there is no "failsafe" built into the controller, but take small comfort in the simple solution of ensuring the two boards cannot separate to being with.

You hit the nail on the head with that one. Last week I received a replacement controller and swapped it out only to have it do the same thing. I figured there was nothing to lose so I opened the controller and as you also found the pin connector that holds the front face to the bottom board was almost completely disconnected. This controller had had some obvious repair work done to it since someone had added a little solder to the top of each of the pins, telling me they knew that there was a problem with these staying connected. I connected it back together as far as it would seat which still was not great but worked much better. I also purchased a new one on hand just in case of failure some cold night and opened that one to look at the connection. The new one was seated all the way down as it should be almost like the connector was a little longer. I do still believe that heat in the hood also causes the capacitors to fail on some so I will be adding some cooling to mine also.

Good info. Mine been fine so far, knock on wood.