Mt. Vernon Control Box ALWAYS GREEN.

[yonderboymc]

I have a Mt. Vernon pellet stove the date punched out on the sticker is May 2005.
I have a problem where the stove thinks there’s a fire in the burn pot if the thermocouple or the stove is the slightest bit warm.
On start-up, the control box light is a steady GREEN so it constantly feeds pellets, to where it cannot start a fire because of SO much fuel.
I can trick it into lighting by switching it to the lowest setting to restrict the flow of pellets.

The local service man has replaced the thermocouple twice, the wiring harness, and the Control Box, to no avail. He also suggested and I moved my thermostat and have the differential set to 3 degrees.
The local service man has also installed a thermocouple grounding kit. I have replaced the Ceramic cover of the thermocouple because it obviously gotten smaller and worn overtime. I have also replaced the igniter because the braided cover on the igniter is chaffed down by the ash pan being taken in and out.
Same problem… The local service man claims he has contacted quadrafire and has no other ideas…

What is the light signals of the Control box? What should it FLASH during the start sequence?

If I put an electric tester on the thermocouple, what should it read? I saw online a Mt. Vernon AE is 15mv or greater, but this an older Mt. Vernon.

Before this started acting up this way, I had (I believe) Snap switch #1 go bad on my Stove, and the blower was shutting down and then the stove was over heating…
What does snap switch #2 DO? Could that be causing the control box to think there is a fire in the box?

Last night I noticed when I placed the heat output control knob to low - it actually turned off the GREEN Light in the Control Box. Does that make sense to anyone?

What Resets the Control Box back to initial start-up?

PLEASE HELP

Any Questions I can answer to solve this riddle PLEASE ASK!

THANKS!
Mike C.

 

[SwineFlue]

I'm not too familiar with the Mt Vernon's, but from the schematic they appear to operate like all the other (non-AE) Quad stoves.

The control box lights are described at the beginning of the Reference Material section of the manual. (It can be downloaded from the Quad web site http://www.quadrafire.com/Owner-Resources/Install-and-Owners-Manuals.aspx) The green light is telling you that the box thinks your thermocouple is over 200 degrees. Normally it turns red when it exceeds 600. Your service guy has already swapped the obvious parts. Does the light turn red after the fire gets going good?

The blue light indicates the control box configuration. How many flashes do you get when you first plug it in? What is the part number on your new box? (s/b something like 7000-206) Quad has updated the box over the years.

Snap Disc #2 will stop the pellet feed if the stove gets too hot by cutting off power to the auger. (#1 turns on the convection fan, and #3 will kill power to the entire stove if it gets too hot.)

when I placed the heat output control knob to low - it actually turned off the GREEN Light in the Control Box

Just a WAG: Look behind the knob, does it and its wiring look OK? No signs of possible damage from the prior overheat... is that when this problem started?

 

[yonderboymc]

Yes I believe it ALL started when Snap Disc #2 went bad and stove kept overheating a few times.

The control knob "looks" fine.

When I plug in the stove I get an ORANGE FLASH then a BLUE FLASH then a GREEN FLASH from the control box.
Then I get a steady GREEN with 6 flashing BLUE.

I checked the thermocouple with a volt meter and it climbed up to 15-18 mv with a lighter.

YES if I put the stove on the highest setting for a minute or 2 the light goes to RED.

On my control box it says:
HHT: 7000-206
SERIAL: 4331
4 speed Board

 

[stoveguy13]

if my memory isn't going bad i think that is what use to happen when the tc didn't have a ground they send a grounding kit now with the new control boxes for the older stoves to fix this

 

[SwineFlue]

The 6 blue flashes is what the manual says you should get. I've never heard of anything like the orange/blue/green flashes, but my box is older and doesn't have the same lights on it.

Does your "orange" come from the same light that can be green or red? Lighting red and green together creates yellow... the control box is supposed to flash yellow if it sees a problem with the thermocouple or its connections.

if my memory isn't going bad i think that is what use to happen when the tc didn't have a ground they send a grounding kit now with the new control boxes for the older stoves to fix this

I was wondering what that was for. He said his service guy installed one. Not knowing what this kit consists of, could it be improperly installed? A poor electrical connection somewhere?

 

[yonderboymc]

Anyone have instructions how the thermocouple should be installed? Currently it's clicked in between the thermocouple and the wiring harness wire and theres a lead to a ring screwed under the upper screw of the Convection Blower # 30 in figure 36.1 @ http://hearthnhome.com/downloads/installManuals/7005_151.pdf

Does it matter which wire of the thermocouple OR the wire on the wire harness? YELLOW OR RED on the wire harness? Figure #33.1 same site as above.
Looks like RED in that figure... I'm not sure what wire it's connected to currently.
I'll investigate this more tonight and report back.

THANKS!
Mike C.

 

[stoveguy13]

was the grounding kit installed before the problem started?

 

[yonderboymc]

I don't believe so...

 

[stoveguy13]

take it out and try it.

 

[yonderboymc]

OH MY GOD! That was it! I removed he ground wire and plugged the stove back in. The control box flashed orange once and then 6 blue lights. I then went DARK!
Dropped pellets for 90 seconds.... and waited...... about 45-60 seconds later a fire started in the burn pot.... about 15 seconds later with the fire burning nicely the LIGHT went to GREEN! About 3 minutes later with the control on high the light went to RED.

Now once the house heats up I'm curious what the control box lights do after it does a shutdown???

Why would the Ground cause it to do that??!!?!? I thought the ground was to prevent bad readings not create them??

Oh well...
Now to keep an eye on it. I pray this was it!

Stoveguy13 you're the BEST!

Thanks EVERYONE!!

 

[stoveguy13]

i think that your wiring harness already had the TC grounded so by putting another one in it messed it up.

 

[SwineFlue]

It then went DARK

That's what the stove will look like when it has shut off and cooled down.

I'm curious what the control box lights do after it does a shutdown?

If you haven't seen it yet... When the room warms up, the call light will go out and pellets will stop feeding. When it cools down a few minutes later, the box red light will turn green and then it will go out. The blowers will stop, but not necessarily in synch with any lights.

Glad you got it working!