When burning “wood” pellets, should there not be smoke?

[kast]

I read a few post recently about the apparent lack of smoke that comes from some peoples pipes (outside) and was wondering should this be the case with all pellets stoves. I know I get smoke from mine, and was wondering if SMOKE = unclean burning, or if some smoke is OK. Should I look into why it is smoking?

I wouldn’t characterize the smoke as looking like my neighbors wood stove, but was just curious after the recent post.

 

[sydney1963]

Smoke on start up only for the most part. I have been playing around with the pellet feed rates on my stove and have noticed that when the flame is very very low or just burning embers for a few moments, when pellets do get to the burn pot there is a tiny puff of smoke that comes out of the vent pipe (outside) until they catch on fire. Is that what you are talking about? There shouldn't be any more smoke than that.

 

[kast]

Yeah I see that when its on 1-2 setting I get enough smoke that I see it pass by my window, and chase the birds from my wife’s feeder  The pellets sometimes burn weird and don’t always stay at a high flame, I got used to that but now I noticed the smoke so…

I have an OAK, but I burned a few bags (5) of some high ash pellets (did not noticed they where high ash) and I was forced to clean out my piping (18 inch horizontal, no Vert) already. First year with the stove was wondering if I should take the blower of the inside and see if there is build-up on the inside causing the pellets to burn erratically.

 

[kinsmanstoves]

As a general rule (remember rules are made to be broken) pellets only smoke when they are being lite or extinguished.

Eric

 

[MButkus]

There should be no smoke coming from the chimney during normal burning...

 

[[email protected]]

I only have smoke at start, when running you can barley smell it with your head next to the chimney

 

[sydney1963]

There should be no smoke coming from the chimney during normal burning...

You are talking about the pellet vent pipe termination (outside) aren't you?

 

[pelletizer]

Pellet smoke is magic you can't see it,

 

[crausch]

My stove only smokes as the pellets are just starting to light. Smoke disipates once the pellets are lit. My manual states the following in the troubleshooting guide:

SMOKE IS VISIBL E COMING OUT OF VENT
1. Air-fuel ratio is too rich.
A. Feed rate too high.
B. Draft too low caused by a gasket leak.

 

[krooser]

My stove only smokes as the pellets are just starting to light. Smoke disipates once the pellets are lit. My manual states the following in the troubleshooting guide:

SMOKE IS VISIBL E COMING OUT OF VENT
1. Air-fuel ratio is too rich.
A. Feed rate too high.
B. Draft too low caused by a gasket leak.

no smoke...

 

[kinsmanstoves]

Pellet smoke is magic you can't see it,

If you are wearing your "special" glasses you can see a lot of things.

Eric

 

[imacman]

No smoke here.

 

[kast]

You are talking about the pellet vent pipe termination (outside) aren’t you?

yup! outside

SMOKE IS VISIBL E COMING OUT OF VENT
1. Air-fuel ratio is too rich.
A. Feed rate too high.
B. Draft too low caused by a gasket leak.

Thanks! I think its really an issue with the lower settings 1 or 2, pellets seem to go low (almost out) then start back up, that's causing the smoke. I just need to find out why its happening.

 

[crausch]

That sounds like that would do it. It doesn't seem like your burn should get quite that low though. I don't think mine does that. When I set mine low, the flame still seems to have almost a torch effect. The flames are real short but they seem to be burning hot because of the air ratio. But then again, my control board tries to maintain all that for me.

 

[rowerwet]

when my pellet boiler is starting a cycle (feeding the fire with pellets and turning on the combustion fan) there is some smoke, once the fire is going there are only heat ripples at the top of the pipe, at the end of the cycle when the fan shuts back off there is smoke for a few seconds also. can you adjust your combustion air? smoke could mean not enough air.

 

[kast]

Can you adjust your combustion air? smoke could mean not enough air.

See that’s the strange part, I think I was giving to much air, and it was probably burning the pellets to fast, because when I placed it on high and tried to dial in the damper again I was able to get a good looking flame with a lot less damper usage. It seems to be running well now heat feels better also.


There is one strange thing I have noticed is even when most of the flame is burning right, I still get some weird lazy flames that seem to keep towards the edge’s and spill over the burn pot.

 

[pete324rocket]

only smoke when really cold out

 

[Jabberwocky]

Same here, no smoke, no smell. This is something to consider if you're considering a purchase and your neighbors are close.

 

[mkmh]

Can you adjust your combustion air? smoke could mean not enough air.

See that’s the strange part, I think I was giving to much air, and it was probably burning the pellets to fast, because when I placed it on high and tried to dial in the damper again I was able to get a good looking flame with a lot less damper usage. It seems to be running well now heat feels better also.


There is one strange thing I have noticed is even when most of the flame is burning right, I still get some weird lazy flames that seem to keep towards the edge’s and spill over the burn pot.

I would guess that you need to blast out your exhaust port. Looks like you have an 05 stove, so if you have not done a thorough cleaning of the exhaust, then that may be what you need to do. Lots of recent threads on blasting or vacuuming things out with a leafblower. My stove was showing the same symptoms as yours, and I (finally) fixed it by applying a tight 6 HP vacuum to my direct vent for 5 minutes. Now I am getting zero smoke, and clean active burns again. I tried pretty much everything else before doing the extreme Vac thing. I was almost ready to sell the stove. Now it is burning like new again.
The worst part about the smoke is that it sooted up the side of my house (burned like that all year last year).

 

[kast]

applying a tight 6 HP vacuum to my direct vent for 5 minutes

Thanks for the info! Can you do me a huge favor and further explain how you did this? what’s the model of the HP vac?

The Stove is an 05 but was bought in 08 burn free, so although I would hope it hasn’t clogged this bad already I would like to know how you went about cleaning, thanks!

 

[mkmh]

applying a tight 6 HP vacuum to my direct vent for 5 minutes

Thanks for the info! Can you do me a huge favor and further explain how you did this? what’s the model of the HP vac?

The Stove is an 05 but was bought in 08 burn free, so although I would hope it hasn’t clogged this bad already I would like to know how you went about cleaning, thanks!

Sure thing. My Vac is a Rigid wet/dry 8.5 amp model (60 bucks or so from HD). I shut the stove down, let it get completely cool, dumped the ash pan...then.
Took the vent cap off the exhaust (I have a DV set-up). Put the hose about 6 inches into the horizontal vent. Wrapped the end vent and hose with about 5 rotations of Duct Tape to ensure a tight vacuum. Fired on the Vacuum and let it go for 5 minutes.
This not only cleared the exhaust, but even cleared out some of the fire box area, as well as the nooks and crannies behind the fire brick.
At some point I will go down and buy some plumbing pieces to connect the vac to the vent, but for now duct tape worked pretty well.

If your stove is an 08 then it does seem unlikely that it is plugged, but this is still a useful trick to have your arsenal going forward. I'm going to make it part of my bi-annual maintenance.

 

[kast]

Thanks! ill give that a try