Pellet Stove Questions (1) Fan Speeds and (2) Smoke on Startup

[petey305]

Hi Folks,


I was running my pellet stove (Quadra Fire Classic Bay 1200) last night and noticed a couple of things:

1) Smoke on Start-up: When the stove first fires up, obviously it creates some smoke in the chamber. It actually gets quite smokey in there for about 5-10 seconds. What I noticed was that near the end of that 5-10 seconds (where its pretty smokey in the chamber), I get a little (and I do mean just the little) whisp of smoke out of the stove. It's so slight that I can't even figure out where it's coming from...It's just enough to barely smell and see. I also have a smoke detector and CO detector near the stove which never goes off it's such a small amount (and this is in a basement with little air movement). My question is...is this normal? It only happens at the peak of smokey start-up. My concern comes around based on my last post:

That post

Is this something that I should be concerned with? I'll keep looking to see if I can see where it's coming from, but since it's such a small amount...it's hard to see. I'm mostly concerned with CO...if this is indicating a leak somewhere (maybe in the stove pipe), I don't want to be pumping CO into the room.


2) The Fan Speed: This stove has 3 heat settings (H/M/L), which from what I can tell just adjustes the auger speed/feed. It also has 2 convection blower settings H/L. The manual states that this allows 6 different settings (2 speed on each of the 3 heat outputs). On the High heat setting, this is VERY noticable. Low speed fan is pretty quiet, and High speed goes up in volume noticable, however, on Medium and Low heat settings...I can't hear/feel any difference in the blower speed at all. Is this normal...or is there something wrong with my fans and/or control box?


Thanks in advance!

JP

 

[Czech]

Pete,

My understanding is that the smoke is normal, my Castile does the same thing. Some of that 'smoke' may be steam from whatever you're burning, I know that corn does this a little more. When I was first adjusting feed rates, the smoke would get really bad if overfed at startup (looked like the box was filled with milk!), my understanding is that the stove dumps more fuel at startup to get going and then levels off. So if you're overfeeding, it will feed even more at startup, thus making the problem worse. As far as it the wisp of smoke, I'd check the door gaskets (front and ash) and vent conections which is probably tough with an insert, make sure the stack is not plugged at all and clean, you probably know all this already! Not sure how the fresh air works on your stove, on mine it is possible for it to leak by the connection to the stove, goes out of the firepot, into the ash compartment, then can leak back by the fresh air fitting. The old incense stick or cig/cigar trick depending on your flavor may help, light one up and pass it around the edges and doors when this happens to see if anything is blowing back into the room. Can't speak to the fan speed, different that what I have. Keep testing that CO and smoke detector! Hope this help, no expert but thought I'd share my thoughts.

B

 

[petey305]

Thanks GotzTheHotz,

Glad to hear that the smoke in the firebox is somewhat normal. I did decrease the feed a bit, mostly because my flame level on high was way to high (manual states 4"-6" above firepot and mine was licking the top of the chamber and rolling all the way around and back down to the glass...so it was more like 10"-12". Hopefully that will help.

As for the whisp of smoke coming out...Hopefully decreasing the feed will help that also (in that not enough smoke will be generated to come out). Of course, I'm still a little concerned with CO. I did confirm that the pipe was free of obstructions so that's cool. I also (just now) reapplied hi-temp silicone sealant over all the joints on the pipe, just to be cautious (no harm in a little extra seal there). Hopefully that will do the trick, but since it's still drying....I won't be able to fire it up for an hour or so. We'll see.

Anyone have any ideas on the blower speeds?

Thanks!

JP

 

[MountainStoveGuy]

Run the blower on the lowest possible setting that will satisfy your heating needs. Less cycles means less electricity pulled for start up, lower blowers are quieter and when parts run at lower speeds they will last longer. Thats my logic
Smoke is normal. The smoking will last longer if the burn pot is dirty, or if your burning cheaper fuel. And a little hint of smoke smell is normal, at least from my experence in burning all there modles for a number of years, not saying that its right, but definatly normal.

 

[begreen]

We almost never get smoke smell at start up. I didn't say flat out never, because there have been rare moments, where once in a blue moon, there is the briefest whiff of smoke. I'm not sure why. It's rare enough that I never investigated. Sounds like you may have cured your stove with reducing pellet feed.

 

[MountainStoveGuy]

All of our pellet stoves installed at the shop have some crazy venting on them. they dump in to a T, then immediatly a 90 to take it horizontal, then a 45 to get it perpendicular to the walls. My building is a octagon with about 80 percent glass. All the holes are predrilled in cinderblock and i dont have any good options for venting. A have always attributed that with the smoke smell i commony get at startup. The smell is very faint and i actually dont mind it. Im guessing that would be different if i were burning corn.
Pellet feed rate in my opinion definatly has alot to do with it too. If your flue collar is not sealed to the pipe on the stove, then it will leak there too.(i would recommend flue tape there instead of red rtv)
Thats expecially true with a complete horizontal termination with no rise.

 

[petey305]

Thanks guys,

Well, I ran this again yesterday, and the same thing happened, although less now that I reduced the feed. I did reseal all the joints on my pipe...I'm fairly certain it's not that. I'm thinking this isn't anything to worry about. Here's my rational:

I only get a whiff of smoke at the very end of the ignition cycle where the box if FULL of smoke, right before it lights. If there was a leak in the pipe, it would stand to reason that I would see smoke coming out from the very beginning of the ignition, until all the smoke is gone after ignition..but I don't. It's only when the fire box is FULL of smoke. So, I'm thinking that when it's got all that smoke in there, it's finding a way out....maybe through the auger or something. From my observation of this stove, the airflow within the chamber is fairly gentle, which probably works fine when it's lit, but when it's smoking up a storm...I'll bet it can't pull it out fast enough before it finds a way out. I can't imagine that this thing is so air tight that smoke couldn't find a way out if it was being generated faster than it could be expelled. I also held my CO alarm right next to all parts of the stove (especially the stove pipe) for quite a while, and the thing never went off. I also held a cig next to the pipe and it didn't appear that there was any leaks affecting the smoke.

Does that reasoning make sense to you guys in the 'know'.

JP

 

[begreen]

Sounds like you've checked pretty thoroughly. You're probably fine. Just out of curiousity, how long is the stove pipe run and how many bends are in it until it terminates? Is there a slathering of RTV sealant where the flue pipe joins the stove exhaust collar? One other thing to check, the door tension is adjustable. You might want to try adding just a little more tension to the two closing clips (doesn't take much).

 

[petey305]

The stove is in the below ground basement, so there is about 5 ft (approx) straight up from the stove, then a 90 into the thimble, then a 90 on the other side of the thimble (to point up outside), a 3 ft lenth, and another 90 into the horizontal end cap. So all told, it's about 8-9 ft vertical, with 3 90 degree elbows. Hopefully not a problem. There is a slathering of sealant where the stove pipe meets the exhaust collar...maybe I'll see if I can scrape off what I can and re-do it. No harm in spending an hour to be safe...I'll also check the door, but if I had to guess, I think the smoke is coming from the back (but then again, with the blower air coming out of the heat exchangers above the door, it would be pretty hard to tell).

Thanks guys.

JP

 

[MountainStoveGuy]

Possibly to many elbows for 3 inch pipe, it might be putting to much backpressure on the combustion blower. You may consider going to 4 inch pipe the minute you go verticle, in that instal i would have a clean out T on the stove, that T would be a 3-4 reduction T. Then all the rest of the pipe would be 4 inch. You might also try just adding more verticle on the outside so some natural draft will help overcome the backpressure. That would be a much cheaper option. You can experement with single wall sections untill you get it dialed in. (on the outside, not the wall pass through)

 

[petey305]

Thanks Again MountainStoveGuy,

Actually...it's already 4" pipe. there is some sort of 3-4" increaser off the stove, and everything is 4" from there.

JP

 

[MountainStoveGuy]

well that rules out that theroy, try extending it with some single wall and see if that helps. Also if your leaking a little smoke at the flue collar the convection blower can suck it up and throw it out the exchange tubes.

 

[petey305]

Ok, so after a few more days of looking, I finally found the problem. There are 2 45's sections in my interior section of pipe. They connect together, to sort of jog the pipe out a bit, so that I can maintain all the proper clearances (kinda hard to explain, but it works). Anyway, I've been looking for the leak source for days and I finally found it. There was a slight leak coming from the manufacturers joint in both those 45's. So minor the smoke just appearing from the side of the 45 with almost no draft. So I used some high-temp silicone and sealed those joints. Voila! No more smoke from the pipe. I still smell the 'faintest' smell of smoke on start up (and I mean faint), but there is definitly no smoke coming out that I can see.

Thanks for the help folks.

Oh ya, and I found that when looking for a leak, the best thing to do is shutoff ALL the lights in the room (even cover the windows that let other light in if doing this during the day), and use a flashlight to track down the leaks. When I had a moderatly lit room, with such a little amount of smoke...it was impossible to find the leak. Doing the room light/flashlight trick, it only took me 3 start-ups to find it, and I got closer to the leak each time. First time, I found it was coming from the left side, 2nd time I found it was coming from somewhere near the 45's, and the 3rd time...I found the problem. Not too bad consider after 10 startups with the room lights on...all I was able to figure out was that it was coming from the stove

JP