quadrafire mt vernon ae error cannot get pass ss-med step (Feb 2009 model)

[b27flx]

hello everyone
can somebody help me with a firing issue ?

stove seems to be running fine until the slow start med (ss-med) step then goes into shutdown mode
the flame looks big (see attached pic) and strong until it it enters the shutdown mode

sometime the error is min firepot temp

please correct me if I am wrong but
tc-droptube looks ok because it feeds the pot with pellets just fine
tc-firepot reads ok because it goes through ss-low, ss-med steps
(meaning to me that it reads the firepot's rising temps)

I suspected the convection fan but when I've disconnected tc-droptube the conv fan starts to blow @full speed
each time I disconnect either TC from the control board it tells me immediately which TC "has failed"

cleaned everything extensively
made sure the tip of the tc-firepot touches the tip or the white TC cover
made sure the tc-droptube ring is not corroded and it touches clean the metal drop tube

could it still be a faulty firepot-tc ? controlboard ? (which is rev C)

to make matters worse the rusty screw that keeps the TC pinned to the firepot has broken

can't drill it out @that angle - i think I've broken 5 drill bits not no avail
does the TC copper needs to be in close touch to the firepot metal? like some sort of ground?

appreciate your help
~peter

 

[kappel15]

If the firepot tc is not being held in place, it won't read right. It is not grounded to the pot. You are not getting a tc error code, but that doesn't mean it can't be bad. You can pull cover off end , unplug from control board. put test probes in end and heat other end with lighter. If it produces millivolts, it should be good. If the braided wires have been bent too much, the coating on wires could of been cracked and will cause the tc to not read right. Best thing to do is to get bolt out of firepot. It goes into a riv-nut on underside, and replace with a bolt,nut, and washer. And be sure to put some high temp anti-seize grease on bolts, so they come off easier next time. And make sure wire is draped in slot with igniter wires, that keeps them clear of auto-clean mechanism. kap

 

[b27flx]

thanks for your quick weekend reply

I took the firepotTC cover out and measured 0000V then put a lighter flame on it
it went up to 0050V until i could not hold the lighter in my hands
then it went slowly to 0000 as it cooled off
can the firepotTC still be bad ?
Is the firepot TC solely responsible for getting past the ss-med towards normal mode or whatever mode turns on the convection fan ?
btw
since I was there I checked the droptubeTC as well
also it produces about 0030V
the thing is even the stove is on OFF the convection fan starts blowing full\high speed as soon as
the droptubeTC is disconnected from the control board (fan reverts back to standing still when the droptubeTC fire is connected back to the control board)

Is that normal ?

 

[kappel15]

The firepot tc keeps the stove running in sequence by sensing the amount of heat. The drop tube tc runs the conv fan by sensing enough heat to turn it on, (100*) and ramping it up when more heat is produced. Is the latch side of the firepot tc towards the droptube tc? If not, it will be out of polarity. Have you checked wires ? Colors match, Connector pins, test for broken wires? #8 on the control board is the Comb blower feedback, and #11 is Conv blower feed back. kap

 

[ljkelly]

The firepot tc keeps the stove running in sequence by sensing the amount of heat. The drop tube tc runs the conv fan by sensing enough heat to turn it on, (100*) and ramping it up when more heat is produced. Is the latch side of the firepot tc towards the droptube tc? If not, it will be out of polarity. Have you checked wires ? Colors match, Connector pins, test for broken wires? #8 on the control board is the Comb blower feedback, and #11 is Conv blower feed back. kap

B27 - I'm having a similar problemthat kap is helping me with. What finally resolved your issue?

 

[naturalburn]

I'm having the exact same issue with my Mt. Vernon AE. Quad techs came out and said I needed a new control board. This is after I spent$300 ($150 and hour) for them to come out and run diagnostics. I told them to leave and replaced it myself from pellethead.com. Needless to say that the control board wasn't the issue. Still getting min firepot temp error after ss-med. It has to be and issue with the temperature reading IMHO. Any suggestions? Im at my wits end and have already spent over $1000. Quad dealer that Is local to me is worthless, they suggested that we stat replacing parts till its fixed. I can do that.

 

[kappel15]

Check that the firepot thermocouple is touching the inside end of the cover, and that the cover is clear of any ash. Also that it is sticking in the pot the right amount per the holder. . Test the firepot thermocouple that it is good. If not, get a new one. kap

 

[naturalburn]

It's completely clean, no ash. I cleaned out the auger removed all the fines from the vacuum tube and cleaned out the hopper completely.

The TC has a good reading. Im at a loss. maybe the vacuum switch. I have the old style square box?

 

[kappel15]

If it was the vac switch, you shouldn't get any fuel. You can try bypassing it and jumping the wires together to see if stove keeps running. Just be careful not to ground the wires out. Try and check and see if auger is reversing now and then. Can you tell if you are getting enough fuel in pot? kap

 

[naturalburn]

I don't know if I'm getting enough fuel. I prime the pot with a small amount of pellets for initial startup but that doesn't seem to help. when the cycle goes to ss-med at some point the auger stops moving and then goes into shutdown. It has to be not enough fuel or temp isn't getting hot enough to get to normal burn stage. The new style tc have that curved end so maybe it's not far enough in the pot. could it be the auger or is the reason the auger stops because the tc isn't reading the proper temp to send it into normal burn?I

 

[Ssyko]

TC is what tells the control board to feed or not. TC should be an inch or so over the edge of the pot and by your pics it looks like it is. Im leaning towards a bad or failing TC

 

[naturalburn]

That's an old photo. I put the old TC from a few years ago back in just to try. The one that I purchased last year is in there now. Here is what it looks like. Its not sitting an inch in there. I can't get it to seat farther due to the shape being like an "S" . I just bought this last year. Is it possible that its bad already? It was the generic version for like $40 instead of the $119 oem. It's just impossible to get it an inch over due to the shape. The old TC didn't have that "S" shape and was straight.

This is the old one that I replaced last year. I moved into the house and the stove has had this issue since I moved in. All of the replacement TC are curved and won't fit into the burn pot the same way as the old one.

 

[naturalburn]

This is the style TC now and it just doesn't fit right into the stove. I guess I'll just buy a new one mt vernon tc but I've spent so much money already. I just want it fixed.

 

[kappel15]

It is not sitting in the firepot far enough. There should of been instructions with the new firepot thermocouple about how to install it. Some stoves you have to drill a new hole for it( 1/8" away from firepot edge on center) and put a bolt in the old hole. Or try to find an older style somewhere. kap

 

[Overfireinthehole]

Not nearly far enough...

 

[Overfireinthehole]

You could try a 90 on your drill with the drill bit but those 90s aren’t designed to have a lot of pressure put on them. I’ve put a self tapper in the bracket before if I couldn’t get the old screw out. Those small impacts come in handy in these situations.

 

[naturalburn]

So I was able to get it rigged enough to make sure it works with the current TC. It ran all night so I'm happy about that. Thank you for the assistance, I (my wife) really appreciates it. After over $1000 and worthless local quad techs it took a few blog posts to figure out the issue. Thanks again. I'll have to look into a more permanent solution with drilling a hole or something. They should just sell a new burn floor piece or something.

 

[Overfireinthehole]

They do sell new burn pots but that bolt has to come out to replace it

 

[kappel15]

You know it has to do with the all mighty dollar that they changed the thermocouples in the first place. I am still running on my original one. kap