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

[BoiledOver]

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.

 

[JTWALL]

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...

 

[McKraut]

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.
View attachment 90698View attachment 90699

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.

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

 

[Leigh]

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

 

[JTWALL]

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.

 

[Leigh]

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

 

[Leigh]

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

 

[JTWALL]

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?

 

[Leigh]

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

 

[JTWALL]

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!

 

[Leigh]

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

 

[JTWALL]

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!

 

[Nofossil]

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.

 

[JTWALL]

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

 

[Nofossil]

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.

 

[easternbob]

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......

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