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



## 700renegade (Jan 24, 2013)

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:
https://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.


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## mikefrommaine (Jan 24, 2013)

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?


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## ihookem (Jan 24, 2013)

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.,


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## 700renegade (Jan 24, 2013)

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.


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## ihookem (Jan 24, 2013)

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.


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## Medman (Jan 25, 2013)

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


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## Jeff S (Jan 26, 2013)

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.


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## dswitham (Jan 26, 2013)

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.


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## mikefrommaine (Jan 26, 2013)

dswitham said:


> 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.


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## dswitham (Jan 26, 2013)

mikefrommaine said:


> 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.


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## dswitham (Jan 26, 2013)

mikefrommaine said:


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


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## Hunderliggur (Jan 29, 2013)

ihookem said:


> 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.



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.


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## ihookem (Jan 29, 2013)

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.


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## 700renegade (Jan 29, 2013)

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......


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## maple1 (Jan 30, 2013)

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

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


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## VTHeatGeek (Feb 7, 2013)

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.


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## weiland13 (Feb 8, 2013)

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.


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## mikefrommaine (Feb 8, 2013)

VTHeatGeek said:


> 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.



2011 model. Has two vents on each side.


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## VTHeatGeek (Feb 8, 2013)

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.


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## All Fired Up (Feb 18, 2013)

VTHeatGeek said:


> 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.



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.


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## VTHeatGeek (Feb 18, 2013)

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.


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## mikefrommaine (Feb 18, 2013)

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


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## JTWALL (Aug 17, 2014)

mikefrommaine said:


> 2011 model. Has two vents on each side.


No offense...but considering the mass of the unit and the temps, I seriously doubt those holes do much in the way of cooling.  Even installing computer cooling fans would do little to lower temps.  I might think about relocating my Eko Controller off and away from the boiler...  Thanks for posting.


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## BoiledOver (Aug 18, 2014)

Sounds like a hit or miss situation. Glad I removed that bonnet from the start and elevated the RK unit up and away from the heat. Heck you could put that thing anywhere.


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## JTWALL (Aug 18, 2014)

BoiledOver said:


> Sounds like a hit or miss situation. Glad I removed that bonnet from the start and elevated the RK unit up and away from the heat. Heck you could put that thing anywhere.


Could you post a photo of how you relocated the controller?  Thanks.


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## BoiledOver (Aug 19, 2014)

Keeping it simple as in photo, or as complex as an imagination could be. Am currently fabricating a control panel that will house the RK, various temp readouts, switches, rheostat and aquastats. The control panel, just as the RK, can be located wherever.


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## JTWALL (Aug 19, 2014)

BoiledOver said:


> Keeping it simple as in photo, or as complex as an imagination could be. Am currently fabricating a control panel that will house the RK, various temp readouts, switches, rheostat and aquastats. The control panel, just as the RK, can be located wherever.
> 
> View attachment 136848


Thanks for the pic.  If I relocated controller, I would have to rewire the entire system  :-(   so I decided to mount a computer fan on the back of the bonnet.  The fan hole is cut; mounting holes for fan are drilled, ...need to cut air intake slot under the Controller.  I noticed there is 12VDC available on the left side of the Controller that I am not using.  It seems to power fan properly.  I will install a fuse just in case things go wrong.  Will post pic when finished.  Hope to get the three capacitors replaced this week...too many projects going!
Regards...


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## McKraut (Feb 6, 2016)

700renegade said:


> 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:
> https://www.hearth.com/talk/threads/eko-40-silicon-door-seals-and-the-new-refractory-brick.88005/
> I was able to find my problem.
> 
> ...



 I realize this is an old post, and an old problem, but it's still around. I just ran into this exact same problem on Tuesday. I found your post, ordered 10 capicitors from Amazon for $10, installed one this  morning, and we're back to burning. Thank you for posting this. You saved me a lot of headache and money!

Bob
I


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## Leigh (Oct 22, 2016)

My eK 40 boiler controller showing an e 1 code any ideas on repairing it


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## JTWALL (Oct 22, 2016)

When [E 1] error appears on the display, it means fault (short-circuit) in the boiler sensor circuit or temperature below 32°F.

I measured the resistance on two different sensors.  At room temp (approximately), the resistance was just under 2,000 ohms.  The resistance should increase at the temperature rises.  Regards.


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## Leigh (Oct 22, 2016)

JTWALL said:


> When [E 1] error appears on the display, it means fault (short-circuit) in the boiler sensor circuit or temperature below 32°F.
> 
> I measured the resistance on two different sensors.  At room temp (approximately), the resistance was just under 2,000 ohms.  The resistance should increase at the temperature rises.  Regards.


If I wiggle the wire around for the temp sensor sometimes I can get it to reset and run for a few seconds before it cuts out and shows e1 again


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## Leigh (Oct 22, 2016)

Leigh said:


> If I wiggle the wire around for the temp sensor sometimes I can get it to reset and run for a few seconds before it cuts out and shows e1 again


Got it to reset temp jumping all over the place and kicking pump on and off


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## JTWALL (Oct 22, 2016)

Have you checked that the screws are tight on the back of the Controller?  Where are you wiggling the wires...near the Controller or near the probe end?


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## Leigh (Oct 22, 2016)

OK got the probe out screws were tight on controller. So I hooked to ohm meter put it in pot of hot water readings seems to be erratic. Is there a way I can be sure wether it's probe or the controller


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## JTWALL (Oct 22, 2016)

With the sensor assembly disconnected from the Controller, perform a continuity check.  Connect VOM leads to sensor wires (polarity is not important). As you flex the sensor wires, the VOM reading should remain stable.  If the reading changes as you flex the wires (or tap the sensor end GENTLY on the table), the sensor is bad.   
Now if you really want to go to the extreme, if you have a 2k Ohm resistor, connect it across the Controller terminals (where the sensor was connected).  If the boiler runs normally, you know the Controller is okay.  If operation is erratic, then the Controller has an issue.
DO NOT keep the boiler running in this condition for very long, since it will not know the water temp is rising.  No sense making an inconvenience a disaster!  Use this test at your own risk!


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## Leigh (Oct 22, 2016)

Looks like the probe is bad. Will get a resistor and check the controller. Thanks for the help


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## JTWALL (Oct 23, 2016)

Okay...I just did the 2k Ohm resistor test on my controller.
First, I disconnected the sensor (with power disconnected).
Turned on power; got the E_1 error code.
Turned off power.
Installed 2k Ohm resistor across terminals 5 and 6.
Turned on power.
Pressed the stop push-button to clear E_1 code.
Controller displayed 71 degrees.

Always disconnect power before making/breaking connections!

Good luck!


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## Nofossil (Oct 24, 2016)

Wow - I have one of the earliest of these, and I never had a problem with it. I stopped using it a few years back because I wanted more precise control over the circulator and fan speeds, but the only real issue is that the green film over the numeric readout kind of crinkled up and shrunk.


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## JTWALL (Oct 24, 2016)

You can disassemble and replace the plastic over the display.  Not very difficult.


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## Nofossil (Oct 24, 2016)

JTWALL said:


> You can disassemble and replace the plastic over the display.  Not very difficult.


Thanks. If I were still using it, I probably would. Good thing to let people know, though.


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## easternbob (Nov 20, 2016)

700renegade said:


> 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.
> 
> ...



700Renegade,
Did you ever get around to tinkering with your temp probe replacement? Any luck with the $1 part instead of the oem part? Mice chew threw the wires on mine last year, but worked all last winter just fine?  BUT all a sudden yesterday the temp is reading really low at one point it was reading 40 then it dropped to 14 now with the probe out in the open air it's reading 0. I spliced the wire to get rid of the mouse chewed sections so that doesn't seem to be the issue. The controller "thinks" the water is below or near freezing so it's keeping the pump on, or at least that's what I assume is going on...
Thanks


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