Help with Mt Vernon Insert

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joescho

Feeling the Heat
Feb 11, 2009
391
Northeastern PA
Hello Everyone: I've been reading up on what everyone has been doing and I hope all of you are well. I have a Mt Vernon AE (2009 ish) insert that is now suddenly acting weird and doesn't follow any of the symptoms and problems I have seen. It would seem that the stove starts up, feeds pellets and ignites. Goes into SS-Low, then SS-Med. The combustion blower is running and doing its thing, but the convection blower never starts. After about 5-8 minutes into SS-Med I get Min Firepot Temp and the stove shuts down (hopper not empty). I did my yearly cleaning along with the chimney months ago and maybe have 1 1/2 bags through this year so I'm confident its not a cleaning issue. The place I bought it from is so backed up and understaffed with service calls that the poor woman at the desk just kept apologizing so I kind of gave up on them. So I started doing some troubleshooting myself, but I couldn't find a whole lot. Since the convection blower wasn't starting I suspected the snap disc on the drop tube, or the thermocouple on the drop tube, or a bad convection fan, or maybe the firepot thermocouple since all of these parts seem to tell the computer when to do what and when based off temperature.

I have jumped the snap disc on the drop tube which I think should fire up the convection blower (I think). Well, it did not. I even took the blower out and made sure it was clean and spun free and it was fine. I also tried testing the firepot thermocouple but my multimeter was jumping around so much I couldn't get a trustworthy reading once I heated the end of the thermocouple. Plus the plug on the end of the thermocouple was so small I had to stick wires in the plug just to have something to put the probes on.

I ordered a firepot thermocouple and want to replace it. This is because its only $50, and its the original TC, and it's not the most terrible thing to do anyway. Plus I saw a video that said the lights on your motherboard blink red for the thermocouple on start up, then change to green when the thermocouple says we're good to go, and the lights never turn green.

But on the other hand, I also read that the thermocouple on the drop tube tells the convection blower when to turn on, and that's not happening so it could be that or a bad blower?

I've had this stove for a while, and this is my first major problem with it so I figure I'm about to become pretty good with all of this.

Am I wasting my time with the thermocouple? If not, I looked at all of it and really can't reach or see that far up where the thermocouple enters the fire pot so if I am to replace it, do I need to remove the firepot? If so, can I reuse the firepot gasket, and will the autoclean firepot floor come out with it or is it 2 pieces?

As you can tell, I've been researching, looking, and thinking but I am really unsure and am not expecting much from the dealer.

Thanks

Joe
 

Overfireinthehole

Minister of Fire
May 5, 2017
737
Miller MO
Sounds like a bad firepot thermocouple if it throws min fire pot temp every time. The ring mount is what turns the convection blower on... I think. It’s been a while since I’ve had to mess with that thermocouple or one of those convection blowers not coming on. If I remember correctly, unplugging the ring mount thermocouple from the board should turn on the room blower and trigger an error. That will confirm you’re blower is good. Do you have the solid for pot tcouple or the braided? Any chance it has been pinched by the auto clean. I think your on the right track with the firepot tc. The comment about the color of lights on a board reflecting TC stages is referring to different Quadrafire stoves that take a different board. Good luck!
 

joescho

Feeling the Heat
Feb 11, 2009
391
Northeastern PA
Sounds like a bad firepot thermocouple if it throws min fire pot temp every time. The ring mount is what turns the convection blower on... I think. It’s been a while since I’ve had to mess with that thermocouple or one of those convection blowers not coming on. If I remember correctly, unplugging the ring mount thermocouple from the board should turn on the room blower and trigger an error. That will confirm you’re blower is good. Do you have the solid for pot tcouple or the braided? Any chance it has been pinched by the auto clean. I think your on the right track with the firepot tc. The comment about the color of lights on a board reflecting TC stages is referring to different Quadrafire stoves that take a different board. Good luck!
Thanks for the help. I actually did myself more damage the other day as I replaced the thermocouple, and broke the pins on the board in the process so that was a fairly expensive screw up. However, I'm in the process of getting a new board but will get someone with better soldering skills than me and out two new pins on that board and use it as a spare.

The drop tube thermocouple is braided. I thought about taking that off and checking for rust or something. I can't see how that can go bad it looks like its just a copper wire hooked to the control board.

I'm so mad at myself!!! I was first worried about plugging it in backwards and not knowing it, then it didn't feel like it was seating correctly on the board is when I snapped them off..... uugh!!
 

joescho

Feeling the Heat
Feb 11, 2009
391
Northeastern PA
If I were to purchase a board myself instead of going through the dealer, would I still need the dealer to hook their config laptop to it and do anything? Is there any way I can tell what fuel tables and such is loaded into a stock control board?

The other question I have is now that I cannot plug in my thermocouple at all, if I unplug the drop tube thermocouple then plug the stove back in, will it do an autoclean, kick the blower on, then throw an error either for the FP TC not being present or the DT TC not being present, or will it just do nothing at all?
 
Last edited:

kappel15

Minister of Fire
Sep 14, 2014
2,489
Iowa
You can purchase the board yourself. Dealer only needs to hook up if they are changing fuel tables, or to diagnose stove. Any recent board should have up to date fuel tables in it. And make sure you route the wire harness for the fp tc up on hanger, to keep out of way of auto clean. Stove will turn on when you plug it in, but will throw a code for the fptc. The ring can get corroded enough to not send a signal also, so cleaning it and area where it connects, could help.
kap
 

joescho

Feeling the Heat
Feb 11, 2009
391
Northeastern PA
You can purchase the board yourself. Dealer only needs to hook up if they are changing fuel tables, or to diagnose stove. Any recent board should have up to date fuel tables in it. And make sure you route the wire harness for the fp tc up on hanger, to keep out of way of auto clean. Stove will turn on when you plug it in, but will throw a code for the fptc. The ring can get corroded enough to not send a signal also, so cleaning it and area where it connects, could help.
kap
Thanks. I will try that. Its one of the aftermarket thermocouples if you wanna call it that. Its got the silver wire on it and does not have the red plastic piece on the thermocouple end. It was like 80 dollars cheaper I think.
 

joescho

Feeling the Heat
Feb 11, 2009
391
Northeastern PA
Update:
Changed the board (because I had to, now I will fix the old board). Changed the thermocouple. No luck. On further inspection, the red wire was never connected in the clip for the new thermocouple so it could have never worked. Got an OEM thermocouple this time. Plugged it in. Still no luck. The tech from where I bought it came out and was stumped too. Said it could be something with the combustion fan because the flame never got really tall and robust like it should so its not getting enough of something. He said the last time he saw something similar it turned out to be the connection from the stove to the chimney was partially plugged and there wasn't enough air circulation. Said he'll be back with the laptop next week. In the meantime, pull the combustion fan and check/clean all that including inside the chamber. I said sure.

After he left I pulled all of it out. As I thought, clean as a whistle - I just cleaned it last June along with the chimney and ran MAYBE 2 bags this year. So I clean the connection, about 1/4 way up the chimney, and inside the chamber. I then got it in my head that I had an auger jam somehow even pulled all the pellets out because I'm now obsessed with that auger jam and its not enough of a jam to throw a code yet not feeding enough pellets to keep it going and get hotter. So I clean the stove and pull every last pellet out then shove the vacuum cleaner up there. Put it all back together and dump pellets in and prime it with a handful of pellets (of course I forget and the damn thing does an autoclean on me - if you have a mt. vernon with the autoclean you know what I'm talking about). I start it up and its slow going and it looks like it going to slowly die again and throw the min pot temp code so give up and I start putting stuff away for the night and hoping the tech can fix me up next week.

About 10 minutes later I see a nice big flame and the convection fan is running!!! I'm fixed!!!!!

I think I had a partial auger jam which ended up costing me a thermocouple and a control board .