Mount Vernon 4 speed miss starts???

[MPC]

I have looked through other threads and can't find this exact problem. I have a Mount Vernon 4 speed (non ae) that I've been having an intermediate problem with for a while. On start up, doesn't matter if it's hot or cold, the exhaust fan starts up, the stove drops pellets for 60 seconds and then it sometimes miss starts and I'll get a faint smoky smell in the room. After the stove shuts down, even thought the red call light is still on and calling for heat, it won't start until you hit the reset button or turn the thermostat off and back on. There will also be a couple handfuls of pellets in the pot that have been partially turned black but never lit up. When this happens the auger still runs for 60 seconds and seems to be dropping plenty of pellets.
I'm also having an issue with a new exhaust blower that shuts down a little early and I get smoke in the house at the tail end of the cooling down cycle. It was doing this prior to changing the blower out too. Had to replace the other one due to high pitch squealing noise.

In the last 2 months I have tried a few trouble shoots:

1-Replaced control board (had a pinched wire that finally made contact and fried my board)

2-Replaced thermo couple

3- tested vacuum switch

4-Vacuum tube blown out

5-Pot holes clean

6-Pellet drop door open

7- checked gaskets on doors and on vent end cap

8- cleaned out auger shoot of all saw dust

9- tried multiple thermostat

10- changed out thermostat wires incase old wires were defective.

11- tested igniter and watched it while in initial start up. The igniter is glowing red.

I did read a post about grounding the thermocouple between the thermocouple wire and the wire that goes to the control box. Is this possibly my issue? I followed the t/c wire up to the control box and I do see what looks like a ground wire next to where those wires go into the board but I'm not sure if that's a ground for the t/c or the control box.
I have checked with my local quadrafire retailer and a local private stove guy and everyone is at a loss at this point.

Any advice is greatly appreciated as I'm loosing my mind with this stove and about to drag it out to the curb.

 

[MPC]

This link is what I'm referring to about the thermocouple grounding

http://nevelsstoves.com/MyImages/quadrafire/QF812-4980Instruction.pdf

 

[stovelark]

Hi MPC- Still love the old quad speed mv. If the stove is missing startups and the ignitor seems to be working... Does the initial dropping of pellets seem to be normal amount?? You mention it sometimes takes 2 startups to get the ignition to happen. On the burnpot bottom, is the cleanout door closed well?? Does it have slop in it?? Only a couple of things affect ignition- the ignitor, the combustion blower blowing hot air through the burnpot- the bottom of the burnpot seal and possibly the door gasket, causing a loss of airflow through the stove. Is the exhaust passages and chimney clean?? All things to check. Of course, you can run the stove on manual mode too, have it run continually on 1 or 2 heat level.... Good luck don't give up on her, still a nice pellet stove.

 

[MPC]

This link is what I'm referring to about the thermocouple grounding

http://nevelsstoves.com/MyImages/quadrafire/QF812-4980Instruction.pdf

The initial dropping of pellets seems to be normal. The door on the bottom of the burn pot does have some slop in it but i always make sure it's closed all the way. The exhaust passages and chimney are clean. The door gaskets seem fine but maybe I should just replace them and see if that does anything. Also I'll tighten down the door on the burn pot bottom.
Btw, have you ever heard of a weak igniter? My local stove store says it works or it doesn't but I'm going to replace it tonight for the fun of it.
Thanks for the info.

 

[kappel15]

There is no such thing as a weak igniter. They either work or they don't. But position in igniter housing is important. And you can remove the igniter and make sure housing is clear of debris or ash. One thing you can do is use a mirror and a flashlight and look in the pot at the slit the igniters heated air comes into the pot thru, to see if there is any blockage of old clinker or some such. And also make sure the 8 small holes are clear in the pot as well. 4 in floor and 4 across from them in pot wall. Once stove calls for heat, it has 4 minutes and 15 seconds to show proof of fire, by the thermocouple sensing 200 * in pot, and starting feeding sequence. You can make sure the thermocouple cover is clean of ash, and that the thermocouple is touching the inside end of the cover. And that it is sticking in the pot 3/4 to 1 inch. And there should be no more then a dimes width gap on the backside of the pot floor. kap

 

[MPC]

I clean all the fire pot holes 1-2 times a day. I also clean the slot where the igniter is. The t/c is brand new and I have ensured the cover is clean and touching the end of the t/c. Today I did a thorough cleaning on the stove, behind the ceramic plates, the whole exhaust system and the hopper/ feed tube. The firepot is seated tightly and the gasket appears to be in good shape. It ran fine for about 6 hours and then a misfire after cleaning. I will check the gap on the backside of the pot door when I get home tonight but I don't recal there being a gap. I will also be changing the igniter out tonight with a new one.

Another thing. After the misfire today, it sat dormant for 2 hours and then magically started dropping pellets again without resetting it. In the past it has always stayed off with the red call light on until you reset it. This is very strange.

Thank you for your ideas.

 

[MPC]

Also, this might or might not be related, but I've been having the exhaust fan shutting down before the convection blower resulting in smoke in the house on the cool down cycle. Could this be related? Is there some sort of sensor on the exhaust fan? Maybe the exhaust fan is shutting it down somehow during start up? It runs on start up even when it misfires but maybe the two are related somehow? FYI, this is a brand new exhaust fan as of 2 months ago along with a new control box.

 

[kappel15]

You can try bypassing the #2 snap disc to see if it keeps happening, but after hearing how it magically started up on its own, has me wondering about the control box. And as I stated before, the igniter either works or it doesn't. kap

 

[stovelark]

Kap- glad you piped in, excellent guidance as always. The oddity of combustion blower shutting down first?? Seems a software glitch, could only be the control board?? Does the combustion blower turn freely, no roughness?? Just wondering. I am still a fan of low and slow, not on and off, meaning to run the stove in manual mode. Good luck with her.

See the exh blower is new now sorry.

 

[kappel15]

Just cause things are new, doesn't mean they can be bad. First question. Is it a stock exhaust fan? Some after market ones people have had issues with. Second question. If you unplug stove, and plug it back in, how many times does the blue light flash, every 10 seconds? Should only be one for standard setting. And is it a 4 speed control box? And final question, did all this start after the wire shorted the old box? Maybe some of the pins where the control box plugs into, got toasted? kap

 

[kappel15]

Kap- glad you piped in, excellent guidance as always. The oddity of combustion blower shutting down first?? Seems a software glitch, could only be the control board?? Does the combustion blower turn freely, no roughness?? Just wondering. I am still a fan of low and slow, not on and off, meaning to run the stove in manual mode. Good luck with her.

See the exh blower is new now sorry.

Not necessarily, if there was too much fuel, it could smolder longer then the exhaust fan is timed for sometimes. kap

 

[MPC]

The exhaust fan is an aftermarket fan I bought from a dealer out of state. He claimed it to be quieter and has never had any issues with them. Plus this issue of misfires and the exhaust fan shutting down first sometimes has been happening for a couple years. It came with the house when we moved in a year ago and the prior owner had the same issues. Even had a certified technician look at it and he doesn't know what's wrong with it. The control box is new as of 2 months ago and yes I had the issue prior to the new control board. It is a 4 speed and I believe it does 6 blue flashes when first plugged in. I'm waiting for it to turn off now before I check again. I know it flashed every 10 seconds as I timed it last night and it was 6-7 flashes. Regarding the blowers, the exhaust fan turns freely now after being replaced. The old one got very loud. The room blower fan started making some squeaking noises a month ago and I sprayed some white lithium grease on it and it's quiet now.

I obviously don't know as much as you guys so I'm just brainstorming. I think it has to do something with something making the igniter not get hot enough, air flow, or the t/c not sensing what it supposed to and working properly. Maybe a short somewhere?
I keep reading stuff about adding another ground to the thermocouple right where the wires from the t/c plug into the other wires that go to the control board. Have you guys heard of this?

 

[MPC]

On a side note, I noticed one of the wire connectors on my snap disc #1 looked burnt. I pulled it off and the contact on the disc looks fine though. Just throwing this out there.

 

[MPC]

Add on thought. While replacing my igniter last night I noticed they had the washer outside of the igniter bracket touching the wing nut side. The instructions with the new one I got said to put the washer between the igniter and the bracket that holds it. Could this have effected anything?

 

[kappel15]

The most that 4 speed box can blink is 3 flashes every 10 seconds, or it isn't a 4 speed box.

 

[MPC]

The most that 4 speed box can blink is 3 flashes every 10 seconds, or it isn't a 4 speed box.

Ok, a little more info. Upon plugging it in, there was a quick orange light followed by 7 blue flashes which were all 10 seconds apart. It's a 4 speed board.

 

[kappel15]

Strange one to me. Is it set on one?

 

[MPC]

Strange one to me. Is it set on one?

Yes it's set on one.

 

[stovelark]

Hi guys- I'm wondering how long the convection blower is running after the call light for heat goes off? It sounds like maybe the exhaust blower isn't running its normal time afterwards to clear out any exhaust gases/burning embers. I'm not familiar with what setting the 4 spd board needs to be on either- it was unique to just the mv 4 spd right?? All interesting data, I'm monitoring for my own knowledge.

 

[MPC]

The convection blower just ran for 70 minutes after the call for heat light went out. No smoke back into the house this time. Smoke back into the house is less frequent than the misfires.

 

[MPC]

I replaced the ignitor 2 days ago. Haven't had a misfire yet but it's not uncommon to go sometimes a week or so without any. The one thing I did notice though, is that the startup time is much faster. Prior to changing the ignitor out, the time the pellets started to drop to when the flame started was on average 5 minutes and 30 seconds. After changing it out I'm right at 3 minutes. Fingers crossed!

 

[smwilliamson]

Aftermarket combustion blower for a 4 speed Mt Vernon????? That sounds fishy... that motor is very specific and it costs $500 bucks. I've never been able to find a suitable AM for this blower, this could very well be your issue.

 

[MPC]

Aftermarket combustion blower for a 4 speed Mt Vernon????? That sounds fishy... that motor is very specific and it costs $500 bucks. I've never been able to find a suitable AM for this blower, this could very well be your issue.

I would agree with you except for the fact that the stove had this same issue prior to changing the blower out. It was the same fan #SRV7000-193 that I put in. The only difference was it didn't come with the housing so I just had to do a little more work and take the fan off the old housing and reuse it with the new fan. I appreciate your chiming in. Feel free to throw me any other ideas you might have.

Thanks

 

[MPC]

It's been more than a week now since I changed my igniter out and not a single misfire. I'm pretty certain that this was the issue now. Previously it was taking 5 1/2 to just shy of 6 minutes for the flames to start when it first called for heat. Now the start times have been right around 3 minutes. I believe I read somewhere that if the thermocouple didn't sense heat within a certain time frame it would shut the stove down. Does anyone know what that time frame is?

 

[kappel15]

You can hear the exhaust fan change speed at 4 minutes, 15 seconds. This is the time limit, but, you actually have a little more time for the thermocouple to sense the 200* needed, to start the feeding cycle, then that. kap