Burning Too Fast - Avalon Perfect Fit

[kstet911]

All - love these forums. Very helpful information here.
I'm a rookie. This is my 3rd season.
I have a quesiton about burn times and too much air getting into my insert.
The Avalon Perfect Fit or Lopi Declaration (same) - has an air control handle on the bottom. Push it in - full air intake. Pull it out - maximum air restriction. What I'm finding is that even when I have this air intake all the way out (closed as much as possible) it seems like the fire is still burning too hot and therefore too fast.
My thought is - either I have some sort of gasket problem - where additional air is coming in through the doors somehow - or there is an issue with how the air control closes off air intake - and that it is not closing it off as much as it should.

Please take a look at my youtube video. It shows the air in take fully out (fully closed) - choking off the fire as much as possible - but still there are a LOT of flames consuming the logs quickly. My burn times seem really low. The manufacturer of my insert state burn times of 12 hours. I've talked to others or read about having 8 to 10 hour burn times. My burn times are more like 3 hours. Given I'll have coals left after the 3 hours - but there really is not much heat to those remaining coals.

After seening my video - is this burning too fast - or do I just have high expectations?

[youtube]http://www.youtube.com/watch?v=Ls_3WtRFtr0&feature=player_embedded[/youtube]

 

[begreen]

The video shows the fire at peak burn. Hard to say if there is a problem from viewing it. Can you describe the flue? How tall is the flue or the liner connected to the insert?

 

[kstet911]

Sure - the insert is attached to a liner that runs approximately 24 feet up to the top of the chimney with a cap.

 

[begreen]

Are you running the stove with the bypass (upper control) closed once the fire is going?

 

[soupy1957]

I own an Avalon Rainer 90 and so I'm familiar with the control on that model stove. Based on your video, it would appear that you are getting SOME closure to the air intake, but not as much as I would expect, if the "damper" was fully pulled out.

HECK, .......when "I" pull our damper knob all the way out, I can choke the fire!! So I understand your concern. I suppose there COULD be something mechanically wrong with your damper control, and I'd further suppose that you could either look it over to see if it is functioning properly, or call in an expert.

The value of being able to close down the air intake fully, given the fact that you can actually snuff out the fire in these type stoves when doing so, is not necessarily worth anything. I can still get a certain amount of secondary burn from our stove, with the damper control only half way out.

Still might be worth looking the mechanism over, to see if it is functioning properly, even if you are NOT going to take the fire to "smoldering" point (which is, in effect, what you get when you kill the flames). Never a good thing!

-Soupy1957

 

[flyingpig]

I have the same model, and it's my first year burning.

From your video, I don't see any strong flame at the bottom front of the log (that were the strong primary intake comes in) so I'm quite certain that the primary air control is at least not at full open. So my guess is either you have some leak, or your flue is drafting too well and the secondary burn tubes draw additional air when you close the primary.


Here is couple video clips of mine. The secondary burn was more subtle, but it may be because I didn't fill it full, and outside temp was almost 50 degree. But in general, the average comment I've got from this site about the model is it won't run 12 hours as advertised. Will be more likely 8 hours max when you pack it full with hardwood.


Full burn
http://www.youtube.com/watch?v=_HOvBYuiBVI

Secondary burn
http://www.youtube.com/watch?v=Mf1pBJxh7GQ


Please try the dollar bill test to verify the door gasket. You're in your third seasons so the original gasket may not be in perfect shape. Also as BeeGreen indicates, make sure you close the by pass damper.

Another question, what kind of wood that you use? Softwood won't burn that long.

Cheers.....Som

 

[begreen]

I own an Avalon Rainer 90 and so I'm familiar with the control on that model stove. Based on your video, it would appear that you are getting SOME closure to the air intake, but not as much as I would expect, if the "damper" was fully pulled out.

HECK, .......when "I" pull our damper knob all the way out, I can choke the fire!! So I understand your concern. I suppose there COULD be something mechanically wrong with your damper control, and I'd further suppose that you could either look it over to see if it is functioning properly, or call in an expert.

The value of being able to close down the air intake fully, given the fact that you can actually snuff out the fire in these type stoves when doing so, is not necessarily worth anything. I can still get a certain amount of secondary burn from our stove, with the damper control only half way out.

-Soupy1957

The air control on a modern EPA stove does not fully close off the air. There is always a certain amount admitted, at least to the secondaries for complete burning of wood gases. Some stoves are simpler and just limit the maximum closure of the primary air.

 

[Todd]

Well, since it's an insert you can't put a damper in the pipe, so maybe you can rig the air supply so it closes down more? EPA stoves have the lowest air setting cracked open a bit and they are tested with a 15' chimney, yours is 24' so it will pull more and burn faster.

 

[Bubbavh]

Seal around the flue connector and check the doors.
Edit: Do the dollar bill test. If it is not sealed well remove the nut from the back of the latch and remove a washer or two.

 

[begreen]

kstet911, is the bypass being closed when the stove gets going good?

 

[kstet911]

Yes - the bypass is being closed when the fire is going good.

 

[begreen]

OK, I thought that was so with a couple seasons under your belt, but wanted to eliminate the variables.

Sounds like you have a nice strong drafting flue. Is this the way the stove has always performed or are you noting a change this year?

If it is new this year, I would first check to see if the bypass is indeed fully closing. If this is not new, there are some ways to slow down the burn. Using larger splits, closely packed and closing down the air earlier are the easiest to try.

 

[kstet911]

Sure - no problem - all questions are welcome.
Just trying to figure this thing out and learn.

Yes - agree - seems to be a strong drafting flue. Sometimes you can hear the whistle of air in there. Not always.
This is definitely not a change this year. It has always been burning this fast. Per reading forums and talking to others - I realize now that it is burning much faster than it should.

When it is cool - I have checked the bypass. I can stick a mirror in the firebox and I close the bypass - and I can see it close the opening in the firebox. Not sure if it is sealing it tight (or if it should) but there is a plate/cover coming across the hole that leads straight out the flue.
What I have noticed about the bypass is sometimes when the stove is starting up (new fire) - the bypass gets stuck - hard to push in. I have a feeling its kind of warped becuase the insert is starting to heat up and the lever that controls the bypass is still cold. Not sure this is normal - but thought I would mention it.

One thing that I don't think I mentioned is that when I close the air intake all the way down - there still seems to be air coming in the front of the stove. I know this - because the log that is laying across the front of the firebox (closest to the doors) - starts to burn out in the bottom middle of the log. It start to burn - turn to coal(s). It looks almost like someone took a bite out of the bottom middle of the log. And you can see that air is flowing in that area because the coals glow red.

Just seems like too much air is getting in.
Someone suggested sealing where the liner comes into the stove. Would that help?

 

[begreen]

So far everything sounds normal, but with strong draft. Sealing gaps in the liner to stove adapter, if there are any, will just improve draft. If all gaskets are in order on the stove, the options seem to be to reduce draft by contstricting the flue or the air supply.

 

[flyingpig]

Sure - no problem - all questions are welcome.

.....
One thing that I don't think I mentioned is that when I close the air intake all the way down - there still seems to be air coming in the front of the stove. I know this - because the log that is laying across the front of the firebox (closest to the doors) - starts to burn out in the bottom middle of the log. It start to burn - turn to coal(s). It looks almost like someone took a bite out of the bottom middle of the log. And you can see that air is flowing in that area because the coals glow red.

Just seems like too much air is getting in.
Someone suggested sealing where the liner comes into the stove. Would that help?

No...that doesn't happen to me when I fully shut it down. The strong primary feed that normally blow in front/bottom of the stove simply stop and there is no primary burn spot there. I guess there is a leak in the gasket in the middle of the door, may be top, bottom or even between doors.

Another close look in your video, I also notice that the fire from the left side is stronger than the rest and it moves like something blow into it...not a typical lazy flame of secondary burn. I'd check on that side also.

CHeers.....Som

 

[kstet911]

I just wanted everyone to see one more video - of how the insert is burning a hole in the front log - right where the two doors meet. Again - kind of looks like a bite being taken out of the bottom center of the log.
Doesn't seem like this should happen. I would think things would be more even.

 

[Todd]

That hole is from that primary air dog house. Seems excessive, can you restrict it some with a ball of tinfoil or a bolt?

 

[kstet911]

I follow about restricting it - but not following where on the insert you are saying to put the ball of tinfoil or bolt. Can you be more specific.
Thanks.

 

[Todd]

Look in the lower front under the door inside the fire box where that air is coming from. Some stoves have a single hole, others have a series of holes or some kind of manifold where that primary air comes out. A few people have plugged those holes with bolts or tin foil to restrict the primary air from blowing into the front lower logs. Sometimes it even helps increase the air wash.

 

[bjkjoseph]

i use my least seasoned wood in my non cat..and save the real seasoned stuff for the cat stove.....if i put the really seasoned stuff in the non cat it would go right up the chimney.

 

[flyingpig]

Look in the lower front under the door inside the fire box where that air is coming from. Some stoves have a single hole, others have a series of holes or some kind of manifold where that primary air comes out. A few people have plugged those holes with bolts or tin foil to restrict the primary air from blowing into the front lower logs. Sometimes it even helps increase the air wash.

Declaration's primary air only blows from the top of the door (air wash). No hole on the bottom.

 

[begreen]

I just wanted everyone to see one more video - of how the insert is burning a hole in the front log - right where the two doors meet. Again - kind of looks like a bite being taken out of the bottom center of the log.
Doesn't seem like this should happen. I would think things would be more even.

Judging by the top flame pattern, that fire looks like it's burning quite nicely over all.

I do see the front, center burn. It would be good to closely examine the sealing of the doors at the lower front on the stove to assert that there is no leakage happening there. Also, clean out the front inside of the firebox and assert that there are no hairline cracks in the front.

 

[oldspark]

i use my least seasoned wood in my non cat..and save the real seasoned stuff for the cat stove.....if i put the really seasoned stuff in the non cat it would go right up the chimney.

So what are you saying the wood is too dry for the non cat and burns up too fast?

 

[flyingpig]

I did my very first overnight burn last night with my FPX33. I packed it 90% with fairly dry oak around 11:30pm, full opened primary air control for 20 min to char the wood, since I've got a pretty strong burn, I've pulled the primary air back almost all the way back for an overnight burn. Things are good at this point

At 00:30AM, I went down and check it again. The Ruthland thermometer attached on the front door (in the middle) showed 550 degree. The actual temp should be +100F (since it's the front door) so it should be 650. That is at least 100 degree higher than my previous secondary burn with less wood. Firebox was full with flame including the flame directly from the wood (like primary burn). I was not sure the temp will continue to rise so I pulled back the control all the way to choke the stove at that point. No sign that the flame get less active. I was worried about over fire at this point.

At 1:00AM, with primary control all the way out (choke) for an hour, the stove temp continue to be the same @ 650F, with the same level of flame in the box. At least I feel safer that the it won't run away, but I still feel that it burns wood much faster than I like.

1:30AM, finally the temp was down to about 570F and a bit less flame in the box. 2 hours from the start and at least 25% of wood is gone. At this point I left the primary control rod all the way closed and went to bed.

7:30AM...the whole house including 2F still be at 70F with plenty of red coal to relight. So I filled it with a huge split of pine and another medium split of oak and went back to bed again.

I feel that the FPX33 primary air control is not strong enough to choke down the fire with a very good draft. I verified that there is no leak around the door. The air from secondary tube is a bit "too much" with a very good draft. I think that it was my fault to let it burn too strong before I choke it down. Once it has a strong burn, it'll be beyond the control of the primary damper.

That gives me an idea that I may be able to solve this by not creating a too strong draft before turn it to overnight burn. I'll try again to night to choke it down a bit earlier and see how the max stove temp & the initial burn rate will be. If thing goes well, I may be able to stretch another hour or two. This may work for the problem with the OP as well.

I'll report back later tomorrow.

Cheers......Som

 

[flyingpig]

Just want to post a short follow up.

I tried the other night to switch to low burn before the temp get too high. This time I switched to low burn when the temp reached 350F with enough flame to sustain the secondary burn. The insert cruise @ about 500F for at least couple hours on secondary burn and I ended up 8:30 hours total with room temp @ 71F and plenty of coal in the morning. I think I stretch it out for 1:30 hour with much more coal left in the morning compare with yesterday.

So, I think it's important for the FPX33/Declaration that we need to switch to low burn before it get out of control

Cheers.......Som