Whitfield Control Board Problem?

[n9122130]

Hello,

Several years ago my wife and I purchased a new home with a pellet stove insert and gas insert. The gas insert was in poor condition and was removed and disposed of. The Gas line was removed from the fire place and capped in the basement. The pellet stove which had worked perfectly year one was moved to the fireplace in the living room and reinstalled where the gas had been previously. No damage was noted to the stove when it was moved and the back of the unit was cleaned. That fall when the stove was started for the first time we encountered a problem which will be described briefly. The Google was used to find a technician who stated that the board needed repairs that he could provide in exchange for money. The control board was sent for repairs this summer. It was returned after a delay and reinstalled in the unit where it presented the same malfunction. The stove is a Model: Whitfield Advantage WP.2. The problem is as follows;

When the stove is plugged in and the START push button in depressed the blower and auger immediately begin operating. The blower should start with this button but the auger is controlled by the ON/OFF toggle switch. The auger runs at full speed regardless of the AUGER SPEED CONTROL knobs adjustment or the position of the ON/OFF toggle switch. The AUGER ON indicator light illuminates as soon as the START push button is depressed and remains on regardless of ON/OFF Toggle switch position. The ON/OFF toggle switch tested good at the back of the board with a multi meter during primary trouble shooting prior to my sending the control board to the technician. It does not affect the system if the ON/OFF toggle switch is in the ON or OFF position prior to the START button being pressed. Currently in order to stop the stove from running the wall power cord must be unplugged, under normal function the ON/OFF switch would be toggled to OFF stopping the auger. Once the stoves temperature was sensed to be in a safe range by the control board the blowers were shut down.

I have contacted the company that was originally contracted to service and repair the board, They had me call their "tech" directly who told me that he replaced the START push button. This never seemed to be a problem. They also replaced the knobs for blower and auger speed control but otherwise nothing seems to have changed on the board. There is flux residue from the installation of the new push button but no other signs of service are present, leading me to believe that the nobs are new but the pots are the same. Is it possible that this is a mechanical issue? It would seem to me that the Board is not recognizing the ON/OFF slide switch. I would like to be as sure as possible that this is a board issue before I send the board back to CA for another service. I understand that this is an older stove and that people familiar with this tech are few but any help would be appreciated. Thank you for any information you are able to provide.

N9122130

 

[Stovensen]

Hello n9122130,

Based on your description, I can deduce that your controlboard is the older type with rotary knobs ( see photo below ). The newer control boards were touch pads types and electronically more advanced with a micro controller serving all functions ( including auto ignitor ).
Also, your description of the symptoms clearly points in the direction of a burnt ( shorted ) auger-triac. The gate of this triac is fed with the timing signal from the pellet feed timer. A shorted auger-triac will keep the auger running constantly, regardless of the position of the feed control.
It is very common for triacs to fail in this way.
So replacement of the auger-triac is the first thing to do. You should be able to point out which of the on board triacs that is controling the auger by following the trace that is connected to the auger in the big molex connector ( pin # 6, brown wire ). I have attached a wiring diagram that will be helpful in the troubleshooting, wire colors etc.
Safety first: Unplug stove before any dismantling is commenced!

Good luck and keep us posted in your progress

 

[n9122130]

Stovensen,

I want to clarify a few things based on your reply. The triac that would be controlling the auger is "on board" in your description. Is this A soldered in part on the control board? I am assuming that when you say follow the trace from the molex. You mean the trace on the control board not a wire into the hardware of the stove . Is this correct? I want to ensure that this is in fact a control board problem and not a problem with hardware separate from the control board. Thank you so much for your answer and the information.

 

[Stovensen]

Stovensen,

I want to clarify a few things based on your reply. The triac that would be controlling the auger is "on board" in your description.

Yes, you've got that right. On the picture I posted, I count at least two triacs on the green circuit board placed on the red background. Look at the uppermost area. They both have aluminum heat sinks bolted to the housing to enhance cooling during action. The housing appears to be a TO220 type, and the exact triac type is printed on the triac component itself. For example, the triacs in my newer Whitfield Quest are the MAC 228 types, but your board is older, and the triacs most likely another type. You'll find out ( a magnifying glass may be needed if your eyes are old like mine ( I'm 62 ) )

Is this A soldered in part on the control board?

Yes it is. I hope you have some soldering skills yourself, otherwise ask someone in your circles to help you. But be sure to have found the correct triac first ( in the US you have Radio Shack, right? ). A single triac is only a couple of $. I would recommend to replace all the triacs and electrolytic capacitors, while you're in there.

I am assuming that when you say follow the trace from the molex. You mean the trace on the control board not a wire into the hardware of the stove. Is this correct?

n9122130, my native language is neither US English nor British English, so there may be some errors in the way I constructed the sentence, when I suggested how to trace the brown wire from the auger that is connected to PIN no. 6 on the white Molex connector. Here's a quote:

You should be able to point out which of the on board triacs that is controling the auger by following the trace that is connected to the auger in the big molex connector ( pin # 6, brown wire ). I have attached a wiring diagram that will be helpful in the troubleshooting, wire colors etc.

Of course, be sure to verify that the wiring harness on your stove is the original with the correct colors! Previous owners could have changed/tampered with things! Once you have made this inspection of the wiring harness and can confirm that it is the original, well then you can be absolutely sure that the brown wire connected to PIN no.6 on the Molex plug is the output voltage - the phase - that makes the auger run. The neutral to the auger follows another path that is also very easy to see on the diagram. Next on the Molex plug, follow the trace connected to the auger, To which triac does it lead?

I want to ensure that this is in fact a control board problem and not a problem with hardware separate from the control board. Thank you so much for your answer and the information.

When making the thorough inspection of the wiring harness, as suggested above, you should also have the opportunity to spot anything looking faulty.
Oh, BTW, one very important question: Is your control board exactly the same model/version as that on my posted picture? Whitfield made several upgrades through the years. If in doubt, please post sharp and detailed pics, so we can be absolutely sure.