Great example of Huffing...

Saw this vid on utube and found it interesting, from what I've read the guy fully believes it is due to a faulty stove.

 

What causes that?

 

Eye-dee-ten-tee error.Notice no flames in the firebox between back-puffs.

 

That looks like it running just like a down drafter to me!
Harmon didn't respond because there is nothing wrong. Down draft stove manufacturers won't ever admit there is any issue, it's always user error in there opinion. Lopi acted like I was the only person on planet earth to experience this smoke belching with the Leyden. I will never own another rear combustion stove!

 

Although, until I got the air adjusted just right last year, I had one of those.
Little puffs of smoke from around the door gasket after a mild BOOM.

 

So... What is going on here?

 

The secondary combustion isn't staying active. It goes out, builds up gas in the firebox and then ignites! They won't do this if the primary air is left open, only when it's shut down or if something is restricting it. But the instructions say to reduce the air once it's up to temp and the bypass is closed. I had 2 Leydens, the first one would puff like that and blow the top lid open, it went back. The second one would run away like a freight train! One night the entire back and flue collar were cherry red and the air was all the way off! They are very unpredictable to say the least. I don't expect to see any of them in production in the near future.

 

I have yet to have any issues with my 300i
Just sayin..

 

What exactly is a "down draft stove"? Ive never heard this term before.

 

Combustion air path flows through an afterburner after a bypass is closed.
Similar action to a cat stove

 

As Webby said it is an intermittent ignition of the gasses in the stove. The right conditions can cause it in many, or in reality any, stove being secondary, cat, or downdraft. Downdrafts are just noted for being the worst due to most of the secondary combustion setups tending to be unstable. This is one of the main reasons also you want all of your flu connections on your stove pipe to be screwed together. It can and has knocked off chimney pipes before and there is nothing cool about a 500* stove pipe popping off during a burn.

 

My old VC Encore was a puffer. Had to play with the air control and find the right spot. Sort of a pain to deal with.

 

I agree 100%

 

I would have agreed with you 100% before owning one of these pieces of crap! They are unpredictable!

 

I remember seeing this video last year. He had several videos and posts about it. Never heard if anything did get resolved with it. That stove was on my short list of stoves last year... Glad I didn't get it!!

 

That's gotta stink up the house pretty bad after a while too..

My VC Resolute Acclaim put out a very small puff once or twice all last year, but nothing like that.

 

Ah, just one of the features of a downdraft stove!

I am super happy that I have avoided this with the VC stoves I have. I've seen several Encores do this.