Secondary Air Probe Opens back up

[Malarky112]

I have an Encore 2550 tha we’ve used for past 11 years. Cat was replaced this year along with new secondary air probe. I really haven’t had many issues with this stove. Would easily get 9-10 hour burns, sometimes longer.
The primary air cable became disconnected and was fixed by professionals this summer. They adjusted the primary air door and now it does not turn down as much as it should I suspect.
So here is the problem, not every time but sometimes the secondary air probe will get hot enough that it will spin around and start opening the secondary air flap back up. Obviously this is a problem and I’m not sure why it’s happening. Attached is a pic of it open while too hot. Normally it starts at the 5 o’clock position and as the probe heats it’s pushes down and closes the flap. It did that but apparently it kept going and opens it back up. I am at a loss here, I am contacting the pros in the morning but not sure what to do about this air probe. I usually have a heat shield in the back of the stove so it’s not easy to get to.
I will also say the wood I am burning right now is pretty dry, we’ll seasoned.
Thanks in advance for any advice.

 

[Malarky112]

I am updating this to hopefully help anyone who might have the same issue

I am on my second air probe after having the first part replaced under warranty.
I even had a buddy who works at a stove shop contact VC. They said that shouldn’t happen (no kidding) and make sure the nut is tight.
My replacement seemed to be working well until tonight out of the blue my stove starts getting hot while I have it turned down. Sure enough the probe was doing it again. I think I’m going to leave it disconnected, the part is obviously not working like it should and it’s a real hazard if you ask me. I never had this issue with my original probe.
VC is producing a dangerous part.
It was not fun taking my heat shield off and the secondary air probe while my stove was at 550 degrees!

 

[Eman85]

I'll have to do some backtracking but I thought I read somewhere that the piece the rod attaches to should be at 4 o'clock.

https://www.amazon.com/ask/question...pful&ref_=pe_623860_70668520_ans_notf_saa_aas This is where I saw it, an answered question on Amazon for the probe.

 

[Malarky112]

I'll have to do some backtracking but I thought I read somewhere that the piece the rod attaches to should be at 4 o'clock.

https://www.amazon.com/ask/question...pful&ref_=pe_623860_70668520_ans_notf_saa_aas This is where I saw it, an answered question on Amazon for the probe.

Yes you are correct, that is where it starts when it’s cold. As it heats, it moves down to 6 or 7 o’clock and closes the air door. The problem is when it keeps going to 9 o’clock and opens the air door back up, feeding more air into an already hot fire!

 

[Eman85]

Yes you are correct, that is where it starts when it’s cold. As it heats, it moves down to 6 or 7 o’clock and closes the air door. The problem is when it keeps going to 9 o’clock and opens the air door back up, feeding more air into an already hot fire!

I was looking at your pic, so that is where it's at when it's hot?

 

[Malarky112]

I was looking at your pic, so that is where it's at when it's hot?

The pic I attached shows it when it’s hot an opened up more then it should be. I will add pictures that show the 3 different stages. The one that is “normal” does not have the rod connected because I took it off to stop it from opening the air flap when it was going too far.

 

[30WCF]

Stealing this drawing from EddyB from the Aspen thread, but it appears the Aspen has a “blocking plate” that prevents the spring from over rotating as temps rise. Possibly irrelevant since these are different stoves, but interesting.

 

[Malarky112]

Stealing this drawing from EddyB from the Aspen thread, but it appears the Aspen has a “blocking plate” that prevents the spring from over rotating as temps rise. Possibly irrelevant since these are different stoves, but interesting.
View attachment 303843

Yes that is interesting and I’m not sure why VC didn’t include something similar. I’m not sure what is supposed to stop it, if there is something internally in the spring. They did say to make sure the nut on the end was tight. It never happened with my original probe so I’m guessing it’s some sort of quality control issue.
I think I could easily add my own limiter by drilling a hole in the cover plate and putting a small nut and bolt at the 7 olclock position so it sticks through the cover and stops the spring

 

[30WCF]

Is the mounting bracket supposed to be straight up and down, or is that where the 4 o’clock position comes into play? Look at the drawing for the Aspen again. It’s bracket is mounted at 4 o’clock. Again, different stoves.

I just don’t want to imply that that’s the right answer. One may be designed to hit a “stop”, and withstand the resistance incurred, and the other may deform if it’s bound up.

 

[Eman85]

@Malarky112 I installed the new probe/coil tonight and it had the secondary air open 1/4" and the end of the coil was at 4 o'clock like it's supposed to be. My wife had the stove going before I got home so I couldn't monitor the exact temperatures but without the cat engaged the secondary air was closed stove top was 575. I engaged the cat and it ran up in the 900's and the secondary air stayed closed. I left the cover off so I can watch it as my cat seems to go crazy with a full load and it's run up to 1600 + on me.
My old probe the end was burnt off quite a bit.

 

[Eman85]

@Malarky112 Bumping this up wondering if you have it functioning correctly

 

[Malarky112]

@Malarky112 Bumping this up wondering if you have it functioning correctly

I’m sorry I didn’t see your earlier response. I ended up leaving mine disconnected because I can no longer trust it. So the secondary air door stays closed now. From what I’ve seen during normal operation it should only be open on cold starts. I’ve had one cold start with it disconnected so far and I did not notice any negative effects.
My buddy who works at a woodstove shop and has worked on stoves for a while actually spoke with another customer who was having the same issue. That customer put foil tape over the opening and stated his stove has never functioned so well as it does now.

I would suggest you continue to monitor it as my second new air probe worked fine for about a week of use before it started malfunctioning.

I would love to hear if you do run into any issues.

 

[Eman85]

@Malarky112 Mine did the same trick yours did. It took off to 1600 and the coil went around and opened the shutter. Mine didn't go crazy it settled down even with the shutter open with the coil on the opposite side. VC never responds, just tells me to contact a dealer.
If you look at my thread about my secondary problems someone linked a different design coil/probe. I am going to look into it tomorrow.

 

[Malarky112]

@Malarky112 Mine did the same trick yours did. It took off to 1600 and the coil went around and opened the shutter. Mine didn't go crazy it settled down even with the shutter open with the coil on the opposite side. VC never responds, just tells me to contact a dealer.
If you look at my thread about my secondary problems someone linked a different design coil/probe. I am going to look into it tomorrow.

Ah ok. I found the thread and responded on there, but that was a link to the primary air control rod. It actually has a coil as well and will close the main air door slightly when it heats up. Totally separate part.