Englander PU-CB04 PCB Troubleshooting

[noobsmh]

I have an Englander 25-PDVC with a PU-CB04 board that is behaving strangely, and I'm looking for some help troubleshooting the PCB.

This pellet stove was brought out from under an exposed shed after sitting for a decade or more. It was given to me by a relative because we were looking for a solution to heat our home while I work on getting the furnace situation in order. We pulled the augers, cleaned out the mouse houses, rust and soot, put it back together and started it up outside to see if it worked. It seemed to run fine, augers fed, room blower turned on when temp got up. Seemed to have no real issues. So, we brought it in the house and piped it up, and ran it.

At some point while I was away, the top auger stopped feeding, and the room blower engages even when well below 70deg F. The wife, noticing that it had gone out, was able to keep it running by feeding pellets through the door. It's almost as if it's stuck in an overheating status, but does not throw an E-3. I suspect a problem with the logic or DC signal on the PCB, and am wondering if there is anyone who has experience troubleshooting at the board level. I know I can buy a new board or get it repaired, but I'm cheap and like fixing things. I know there was a member here with the Englander team, but I can't remember the name, and think I saw that their last post was in '22.

TLDR - Started up fine after a decade of storage, then upper auger stopped running and room blower won't turn off at low temp

Here is a synopsis of the current behavior:
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-Normal display upon switching on at power strip *most* times
-Rarely display goes all wonky and blinks / does not display normal characters
-One time there was no display when switching on at power strip, corrected by unplugging / replugging

-When using "on" switch on stove, it starts the combustion blower, igniter turns on, lower auger turns, then after a few seconds, the room blower turns on, but the upper auger never cycles.

Here is what I've checked so far:
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-Vacuum switches work fine. Jumped the combustion blower switch to be sure there, and the burn chamber also confirmed good by running the upper auger manually with the on switch
-Temp sensor bench tested good, but replaced anyway to be sure, still no change in behavior
-Blowers run well
-Upper auger motor/transmission bench tested good and works with on switch when vacuum switch activated
-PCB solder joints *look* good, the thing seems to be built like a tank, no clearly damaged components
-Transformer output of approx 10V for each set of outs and 20V in series
-DC voltages of approx. 12V and 5V after rectifiers and signal smoothing caps, but don't really know how to test the consistency of the signal

Is it possible that the memory in the controller got corrupted? Any way to re-flash ("Pellet Rev12")? Any thoughts on what else I can check for?

Many thanks in advance.

- noob shaking my head

 

[noobsmh]

I did perform the reset and made sure I had the correct mode value (d) and factory settings (6,4,1)

 

[ARC]

Your stove has modes A,B.C and D should be in D mode. Make sure your Air on Temp is set on 1.

Have you checked what mode your stove is running in D is default C is hotter, A and B are for other stoves.

Could you check what mode your stove is set at: Should be D mode.

Unplug the stove
Plug power lead back in and press both the up and down blower speed buttons at the same time within 4 - 5 seconds and then release the buttons, you should now see a letter (A, b, c or d) in the left or right digital display under heat range or blower setting, you need to change this to 'd' using the up / down buttons below that readout once set to 'd' wait 10 - 15 seconds then unplug the power again and wait 5 seconds. (Sometimes the mode that you want does not set and defaults back to the mode that it was in before, repeat this step to make sure the mode that you want is set.)

 

[ARC]

Does your Englander have a hopper switch? Some do some don't. You would think that it is a work no work part but sometimes when they go bad they do weird things.

Hopper Lid Safety Switch
This unit is equipped with a hopper lid safety switch (Part # AC-HLSB) which is directly
connected to the top auger motor. In the event the hopper lid is left open while the stove is in
operation, the hopper lid switch will prevent the top auger from turning. This is to prevent byproducts
of combustion from entering the home through the open hopper lid and also to simply prevent
operation with the hopper lid open.
Improper hopper lid safety switch operation will result in a top auger that will not turn and
therefore a stove that will not burn. NEVER place your hand or any object near the auger while the
stove is connected to power.

https://www.hearth.com/talk/threads/25-pdvc-hopper-safety-switch.185885/

 

[noobsmh]

Does your Englander have a hopper switch? Some do some don't.

Hopper Lid Safety Switch
This unit is equipped with a hopper lid safety switch (Part # AC-HLSB) which is directly
connected to the top auger motor. In the event the hopper lid is left open while the stove is in
operation, the hopper lid switch will prevent the top auger from turning. This is to prevent byproducts
of combustion from entering the home through the open hopper lid and also to simply prevent
operation with the hopper lid open.
Improper hopper lid safety switch operation will result in a top auger that will not turn and
therefore a stove that will not burn. NEVER place your hand or any object near the auger while the
stove is connected to power.

No hopper switch. I contacted SBI tech support. The board is in a permanent state of overheat protection. They do not have any technical information on the board, so I'm stuck with reverse engineering or getting it repaired by SAO / purchasing a new one. Unless, of course, someone has some experience with the board and is willing to assist. Thanks for trying to help!

 

[ARC]

Are you original owner if not someone could have removed hopper switch and splice wire together PU CB04 board should have switch. Follow wire from vacuum switch back to the board. Should go to hopper switch or #4 pin on plug. $350 for new board hurts.

 

[noobsmh]

Are you original owner if not someone could have removed hopper switch and splice wire together PU CB04 board should have switch. Follow wire from vacuum switch back to the board. Should go to hopper switch or #4 pin on plug.

View attachment 340923

My model did not come with a hopper safety switch. There is a diagram on the rear panel that confirms this.

 

[ericofmaine]

Not all of these stoves came with the hopper switch (mine didn't and the diagram still shows it). Just as one final piece of troubleshooting, did you try swapping your auger wires? If your top now runs and the bottom one doesn't then I would agree that you have a board issue. With your room blower coming on at the start, I'd lean that way anyways.
You might have to shop around for a new board. I went on Englander's site last year to check and they weren't available through them anymore.

Eric