Cab50 power problem

[Mr.Dee]

Hey there,
I have an Eco-cab50 that has been working well enough since I bought it new in 10/14. (Had to replace thermocouple two years ago). Has been meticulously maintained and all guidelines have been followed. (I live on a low fixed income so my rule of thumb is buy big ticket items brand new and take care of them as perfectly as I can.) All vents are entirely cleaned out several times a year, and at the end of the season.

I used the stove half a dozen times starting a few weeks ago. (used 5 bags or so). Last week I turned on thermostat and heard nothing. I checked out the stove, saw no call light, no fans, no life. I unplugged machine, plugged it back in, hit reset button; still no response. Followed trouble shooting guide and found what looked like a bad fuse. (The glass wasn't dirty or stained, but I didn't see any element inside the tube at all, so I figured perhaps it had burned away entirely without leaving residue.) So I replaced the fuse, but still nothing. I unplugged the machine, then inspected, cleaned, unseated/reseated every connection in the machine. I reset the snap-discs, reseated the control board, cleaned out the pellets and vacuumed the auger area clean, inspected thermostat wires, reseated them as well. Everything was spic and span. Nothing.

I used a pen light to determine where power was flowing. It flowed into the vacuum monitor switch (red line coming in), but didn't flow out. I jumped the wires together, but still nothing. (I also verified that power was flowing to the gray wires that lead into and out of snap disc 3.)

I decided to take a shot and order a new vacuum switch ($44.97) but that didn't solve the problem. I recleaned exhaust pipes (nothing there really) in case a vacuum was part of the problem. (BTW, I did the paper test on the gasket and the paper is really tight on the bottom of the door, but comes out more loosely at the top of the door. Could a poor seal on the gasket cause a total stoppage of power?) Still nothing.

Lastly, this AM I had the control box out and was going to drive to my dealer to see if they could test it for me before I drop $250 on a part I may not need. I decided to put a small wire into the nipple for the vacuum line going to the monitor. I didn't feel any resistance and it went several inches in. There was no sawdust on it when I took it out of the nipple. I put everything back together, put the control board in (but I didn't tighten it down!). When I plugged the Cab back in, it started up! However, instead of going through the typical fifteen minute initialization, it immediately started dropping pellets and it started a fire. But it kept on dropping pellets in large numbers, the fire got very large, so I lifted the hopper hood to cut off pellets. I let it burn itself down, cool off. I unplugged the power, rechecked fuse, reseated control box fully, reset all the snap discs, hit the rest button, plugged the Cab back in: Nothing. Back to what I had last week.

So, I'm thinking it's the control box. I'd normally buy it from the dealer, but they're so busy they don't answer the phone and their message box is full. I can order it on-line, but I worry about the quality of big ticket electronic parts.

I value your opinions! Thank you,
Frank

 

[kappel15]

Usually if you hit the tstat and nothing happens, it is the tstat or tstat wires, whether there is a bad spot in wires or bad connection at tstat or stove. And never remove or install a control box, without unplugging stove first, or you run the risk of toasting it. I would still take the box to the dealer and have him test it in a stove or on equipment if he has it. kap

 

[corkman]

Disconnect the tstat wires from the back of the stove and install a little jumper wire and see if will run manually.

 

[Mr.Dee]

Usually if you hit the tstat and nothing happens, it is the tstat or tstat wires, whether there is a bad spot in wires or bad connection at tstat or stove. And never remove or install a control box, without unplugging stove first, or you run the risk of toasting it. I would still take the box to the dealer and have him test it in a stove or on equipment if he has it. kap

Thanks, Kap, for the reply. Unfortunately the lack of power shows up from when the stove is first plugged in. According to the manual and my experience with the stove, whenever it is unplugged and then plugged back in, the stove is supposed to do some kind of initialization for 15 minutes or so. After that's over, the manual says we can turn up the Tstat. But since my stove never responds to the power at all, the trouble shooting guide says the problem is with the control box or snapdisc3.

So I think you're right about taking the control box to the dealer to test, but this morning they told me that they don't have a way to test it. And they also don't have a CAB 50 on display to test my box in, and their one and only mechanic is booking 1.5 months out. ($120 for first half hour, $92 an hour after that!) I'm not real impressed with my local dealer's ability to respond to customer repairs...

I am leaning towards replacing the control box.

 

[Mr.Dee]

Disconnect the tstat wires from the back of the stove and install a little jumper wire and see if will run manually.

Thanks, Corkman. I did try that and still had no response at all from the stove.
I think the problem is with the control box, but maybe there's some other reason for the stove not even coming to life when it's plugged in, and yet power is running through the wires and up to the vacuum switch. I'll keep digging. Thanks for helping out!

 

[kappel15]

Try jumping the #3 snap disc wires to bypass it and see how it goes. It is a process of elimination. I would also try cleaning the tabs on the control box and the insert it goes into. Might be a little corroded and not making contact. You are correct that when a stove is plugged in, the exhaust fan should run for a while.

 

[Mr.Dee]

Try jumping the #3 snap disc wires to bypass it and see how it goes. It is a process of elimination. I would also try cleaning the tabs on the control box and the insert it goes into. Might be a little corroded and not making contact. You are correct that when a stove is plugged in, the exhaust fan should run for a while.

Kap,
Okay, jumping number 3 snapdisc sounds like a good idea and it's something I haven't done. Would be nice to only have to replace the snapdisc.

And thx for the tip on cleaning tabs and contacts. A computer guy once taught me a trick I still use: gently rubbing a clean pencil eraser on the contacts and then brushing away the rubbings. Seems to work every time!

I'll let you know how the jump works on #3. Thanks.

 

[Mr.Dee]

Hey, all. Follow up to above:
I tested snapdisc 3 and the power was flowing through it, so I bought a new control box.
After installing and plugging the unit in, the "self-test" started up normally! I let the CAB50 go through its testing (takes about 10-15 minutes or so).

Once the machine was done, I switched on the thermostat and .... nothing. No call light, no response from machine. I pressed the main reset button but nothing happened. I lowered the thermostat, unplugged the machine, waited, then plugged it back in so the control box would start the self-test all over again, but this time, NOTHING.

Everything is the same as before the new control box (which did the self-test just that once). Power is flowing through the fuse connections, flowing through snapdisc3, and reaching the vacuum monitor (which is new, unnecessarily probably).

So, my question to those knowledgeable in CAB50 is whether or not there is something else that would prevent a control box from coming back on? I have checked for vacuum, checked for clearance of all exhaust ducts, reset every button/snapdisc. I'm at wit's end. I left a VM with the dealer hoping they can get their service person to contact me (apparently he is very overbooked), but I won't have an answer to my phone message right away (they don't tend to their answering machine a whole lot).

Any insight is greatly appreciated. Right now I'm leaning towards Eco-choice/Heatilators being an example of poor quality and poor customer service. I wish I could install a wood burning stove!

 

[Mt Bob]

Need Kap for this.But,I recommend trace wires from t/stat connector to the reset button,and see if it has rubbed through somewhere.You may have to disassemble the junction box and check inside.

 

[Mt Bob]

Would not hurt to check for loose wire on back of heat output switch,also.

 

[Ssyko]

You could unplug the stove pull the board and reinsert, it may just be a connection issue. Other than that id have to get a multimeter out and test wires

 

[Mr.Dee]

@Bobare and @Ssyko
Thank you both for the insight. I have indeed examined and reseated tstat wires, and traced/examined all wires in the stove and power supply. Even went into the junction box and it is immaculate. Control board contacts are clean, and now that I have a new control board, they are perfect. Connector to the junction box is also clean. I've reseated every connection I could disconnect, and all look clean and good. No corrosion anywhere. I've experimented by jumping past #3, #1, and vacuum monitor. Nothing works.

Hopefully Kap may have seen something like this that is causing a signal to be sent to the control board telling it to not do anything when it gets power. I've cleaned out pellet auger, hopper, all vents, all exhausts. (Everything was cleaned at the end of the winter anyway, but I did it again). My power comes from a surge protector, so the power isn't frying the boards. Plus the machine has been working in the same spot for 3 previous years.

So, either something in my machine keeps frying control boards, or something in my machine is telling the control board to not let the self-test begin. If I'm lucky, it's some kind of initialization thing. (Though I have reset every snapdisc as I reseated them.) BTW, I've done these tests and procedures multiple times. Probably spent 20 hours on back on this machine in the three weeks it hasn't been running. Man, I loved the ease of dealing with pellets instead of chopping wood, but to have this much problem on a well-maintained machine is really testing my patience.
Thank you again for trying, and thanks for the insight as it confirms lots of what I have encountered so far.
Frank

 

[Ssyko]

I ment to reseat your control box. And for testing purposes i would eliminate the tstat (jumper)till you get the stove going.

 

[jzm2cc]

Does the red call light come on when turning up thermostat or shorting across the external terminals? If not check the thermostat circuit wires on the inside of the cabinet that plug into thermostat circuit connector. Try disconnecting these two wires and touching them together to see if red light comes on.

 

[kappel15]

Do as suggested, on jumping across screws on stove that tstat wires go to. Process of elimination of tstat wire problem or tstat problem.kap

 

[Mt Bob]

That is a simple stove,and appears they have not changed it for years.Looks to me like the t/stat,heat control switch,reset button and call light are all low voltage.There should be a green blinking light,inside the control box,when plugged in but not running.The reset button is inline with the t/stat,does nothing if the stove is unplugged.You may have a bad reset button,or bad heat switch,you can spray them out with cleaner,and test with ohm meter.Or,you may have a bad connection somewhere else,even a broken wire inside a connector.Or,2 intermittent problems,and,when t/stat signal does work,the combustion blower or igniter has a short to ground.Voltage surges can sometimes cause logic lock up in circuits,your box may still be good.I would unplug stove,pull box,or swap,unhook t/stat,reinstall box(wait 30 minutes),plug in and see if it starts the initialization procedure.If it does,I would unplug combustion blower and igniter,without unplugging stove(have to be careful),then jumper t/stat connection,see what happens.You may have to try it with both boxes,your first one has been through a lot.Also,do not install screw in box,so you can gently move it,to look for a reaction.Also,if you do not want to wait 30 minutes every time,unplugging the box,you can unplug the stove,and go across both flat terminals on the wall plug,this dumps all the capacitors,and memory.This is an old mechanics and PC repair trick,cannot hurt anything.I am leaving you link to the technicians repair manual,and,the wiring diagram will tell you lots,if you know basic circuits. https://downloads.hearthnhome.com/communications/ECO PELLET_consumer_serv_man.pdf

 

[Mr.Dee]

I ment to reseat your control box. And for testing purposes i would eliminate the tstat (jumper)till you get the stove going.

Hi, Bob,
Yeah, I definitely have reseated the control box several times. Just now I jumped the tstat, plugged in the unit, and still no response at all. I bet something fried the brand new control board, but absolutely nobody has a clue and my dealer support is useless.
Thanks,
Frank

 

[Mr.Dee]

I ment to reseat your control box. And for testing purposes i would eliminate the tstat (jumper)till you get the stove going.

Sorry , Ssyko, I sent my reply to you to BobBare!

 

[Mr.Dee]

Does the red call light come on when turning up thermostat or shorting across the external terminals? If not check the thermostat circuit wires on the inside of the cabinet that plug into thermostat circuit connector. Try disconnecting these two wires and touching them together to see if red light comes on.

Absolutely nothing happens with the stove at all. No call light, no fans, nothing. I have jumped the thermostat connectors on the outside of the unit, but not on the inside. I assume I have to open up the junction box to get to the inside tstat wires so that I can touch them together while the unit is plugged in, which means the control board isn't seated. Correct me if I'm wrong. I'll do this tomorrow. Thanks, JZM2cc

 

[Mt Bob]

Green light flashing inside control box?

 

[Mr.Dee]

That is a simple stove,and appears they have not changed it for years.Looks to me like the t/stat,heat control switch,reset button and call light are all low voltage.There should be a green blinking light,inside the control box,when plugged in but not running.The reset button is inline with the t/stat,does nothing if the stove is unplugged.You may have a bad reset button,or bad heat switch,you can spray them out with cleaner,and test with ohm meter.Or,you may have a bad connection somewhere else,even a broken wire inside a connector.Or,2 intermittent problems,and,when t/stat signal does work,the combustion blower or igniter has a short to ground.Voltage surges can sometimes cause logic lock up in circuits,your box may still be good.I would unplug stove,pull box,or swap,unhook t/stat,reinstall box(wait 30 minutes),plug in and see if it starts the initialization procedure.If it does,I would unplug combustion blower and igniter,without unplugging stove(have to be careful),then jumper t/stat connection,see what happens.You may have to try it with both boxes,your first one has been through a lot.Also,do not install screw in box,so you can gently move it,to look for a reaction.Also,if you do not want to wait 30 minutes every time,unplugging the box,you can unplug the stove,and go across both flat terminals on the wall plug,this dumps all the capacitors,and memory.This is an old mechanics and PC repair trick,cannot hurt anything.I am leaving you link to the technicians repair manual,and,the wiring diagram will tell you lots,if you know basic circuits. https://downloads.hearthnhome.com/communications/ECO PELLET_consumer_serv_man.pdf

Hi, Bob,
This is a good bit of advice and I will follow up on it. As I said, absolutely nothing happens when the unit is plugged in, even after waiting hours. I appreciate the link to the manual, which I read and have followed for two weeks. I do admit, however, that I do not have the equipment required to test for continuity, and though it can be said that I know basic circuits, I don't have the ability to figure much out in real life. Apparently my area is very low on qualified pellet stove techs so I will have to wait a long time for help.
I'll try your ideas tomorrow.
Best,
Frank

 

[Mr.Dee]

Green light flashing inside control box?

Nothing I can see. Maybe I need to check again tomorrow.

 

[Mr.Dee]

Do as suggested, on jumping across screws on stove that tstat wires go to. Process of elimination of tstat wire problem or tstat problem.kap

Yes, good idea. I did that and nothing is happening.

 

[Ssyko]

Ok just for a last reort is there power at the outlet/ surge bar?

 

[Mr.Dee]

Ok just for a last reort is there power at the outlet/ surge bar?

I understand why you might ask, but, yes, there is power. I have tested other devices at the surge protector (all worked), and have used two different power cords with the pellet stove (both worked).

Tomorrow I'm going to try everything you folks here have mentioned. I appreciate everyone's advice.
FD