Help Diagnose! Low temps that I can't maintain!

  • Active since 1995, Hearth.com is THE place on the internet for free information and advice about wood stoves, pellet stoves and other energy saving equipment.

    We strive to provide opinions, articles, discussions and history related to Hearth Products and in a more general sense, energy issues.

    We promote the EFFICIENT, RESPONSIBLE, CLEAN and SAFE use of all fuels, whether renewable or fossil.
Status
Not open for further replies.

KSgrown

Member
Dec 1, 2010
80
Kansas City
New Century Heating cw2500, see this thread if you are unfamiliar. Also to see pictures of my setup (I'm not the OP in this thread):
https://www.hearth.com/econtent/index.php/forums/viewthread/67504/

Only been burning for a week in our new 2cuft firebox fireplace insert. We have a large masonry fireplace with an exterior chimney, 23' of insulated flex king pro. I have gotten the temp up to 450 degrees probably once or twice, but shortly after it will cool. I have a tough enough time maintaining 350deg. Our coal bed gets very large cause we continue to burn, trying to get up to temp, but still can't. Without the air wide open, the fire tends to smolder. Even when it's hot, lots of coals, and throw on a big one and lower the air, it only seems like we see secondaries for a few minutes. Also, I looked up the flue today, after one week, and found a thin film of very powdery creosote. Probably not the best sign...

I got a fair amount of wood, but I guess it isn't as dry as I thought. The walnut tree was cut into 18" long rounds two years ago and it laid on the ground till we split and stacked it this Thanksgiving. No, I don't have a moisture meter yet. The logs appeared dry but I it must be the dark color of the walnut giving that illusion. I need to go to home depot and pick up a meter but don't feel like fighting the new snow.

Is there anything else that can be causing this before I blame the wood? Too much draft?
 
It is likely the wood. While at the HD pick up a kiln dried 2X4 and see what the stove heats up to with that, if it takes off you know it is the wood.
 
I would also suspect the wood....even though it was on the ground, if it was not split then there is probably still a lot of moisture in the wood. I like Hurricane's suggestion as a test.
 
The rounds were very large, 24-30" in diameter. So by the time we split them down to something small enough, we got LOTS of splits from just one of these rounds.
 
KS-4-Life said:
Is there anything else that can be causing this before I blame the wood?

Blame the wood.
 
Forgot to add:

firewood_t-shirt2.jpg
 
KS-4-Life said:
I have gotten the temp up to 450 degrees probably once or twice, but shortly after it will cool.

Where is your temp gauge? You won't get an accurate measurement on top of the firebox because there is a gap between that metal and the firebox for the fan to blow air through. I have the exact same stove and have tried placing the gauge on the top left corner of the front of the stove (right by the air intake). But even here I think it's not as hot as the top of the firebox would be. I've only had the gauge for a few burns myself and haven't gotten it over 450 either but they have been smallish fires.
 
Almost any time you are getting low temps its the wood. That being said you will get more heat with the air control closed then open. I did notice you said the fire wants to go out when you turn the air down.....so again its the wood. Do you have any stores around you that sell the wood in a bag? If you do pick up a bag or two. You will see what happens with better then average wood.
 
That wood will peg the meter when you re-split a piece and test it.

It was split on the wrong Thanksgiving.
 
BrotherBart said:
That wood will peg the meter when you re-split a piece and test it.

It was split on the wrong Thanksgiving.

Sad to say, BB is correct; wrong Thanksgiving. You can't expect too much heat from poor fuel.
 
pen said:
Here is some suggested reading that will; hopefully put you on the better side of the burning wood enjoyment coin.

good luck

pen

Thanks for that, I will read up!
 
Scottydont said:
Where is your temp gauge? You won't get an accurate measurement on top of the firebox because there is a gap between that metal and the firebox for the fan to blow air through. I have the exact same stove and have tried placing the gauge on the top left corner of the front of the stove (right by the air intake). But even here I think it's not as hot as the top of the firebox would be. I've only had the gauge for a few burns myself and haven't gotten it over 450 either but they have been smallish fires.

I'm still waiting on my stove t'stat from NT. It was supposed to ship from the factory but I haven't seen it in over 2 weeks. So, right now I'm using an infrared thermometer and shooting the front of the firebox, above both corners of the door. Sounds like the same place you are measuring.

So, the temps might be a little low, but still. Taking the temp in this location, tonight it's reading between 375 and 400, which is better than it has been before.
 
BrotherBart said:
That wood will peg the meter when you re-split a piece and test it.

It was split on the wrong Thanksgiving.

I went and bought a meter from HD. Unfortunately they only had 1 in the store, a Ryobi "Pinless" moisture meter. It doesn't have the metal probes but instead uses these soft sensors on the back to prevent damage to construction materials. While this is probably fine for drywall and trim, I'm guessing not the best for firewood. So, I grabbed some of the walnut splits and split them again. The inside appeared wet; you could tell that the interior of the wood was damp. The new meter read 18% on the outside and 25-32% on the newly split face.
 
KS-4-Life said:
I went and bought a meter from HD. Unfortunately they only had 1 in the store, a Ryobi "Pinless" moisture meter. It doesn't have the metal probes but instead uses these soft sensors on the back to prevent damage to construction materials. While this is probably fine for drywall and trim, I'm guessing not the best for firewood. So, I grabbed some of the walnut splits and split them again. The inside appeared wet; you could tell that the interior of the wood was damp. The new meter read 18% on the outside and 25-32% on the newly split face.

Would it help me out any to split my wood another time and store a couple days worth in the garage before I burn it? I have room for maybe a weeks worth of wood in the garage, and I can replenish as I go, to try and further dry it out. From burning it, looking at it, and now using a meter on it, I think I am not too far from dry wood. Maybe a re-split and drying a week in the garage might help?

Just thinking out loud here...
 
It should help, especially if there is heat in the garage or if you point a fan at it.
 
I had a friend tell me that Walnut needs a lot of air and works better in a traditional fireplace. He said that he breaks his Walnut down to small pieces for burning in the stove otherwise it doesn't burn well. Is this true? I figured that it's a hardwood so it should be fine for my insert.

Do you think that this is true about walnut? Do many people around here use this hardwood for fuel in their stoves? I've been measuring the moisture at 32%, which is at the upper limit of what I read on another thread and I think is a FAQ on here somewhere:
https://www.hearth.com/econtent/index.php/forums/viewthread/68040/

I did get the insert up to a good temp, finally max'ed out my infrared, which is at 500. I only burn on evenings & weekends so my learning curve is not very steep.
And I've got a stack started of pretty small splits in the garage (40deg) and got a box fan blowing on it, maybe that will help my wood issues.
 
I've burned alot of walnut in a wood stove and never had any trouble with it.
 
wkpoor said:
I've burned alot of walnut in a wood stove and never had any trouble with it.

Thanks, I figured walnut should be fine, I just needed a little encouragement.
 
Isn't the rule of thumb that to burn easily and cleanly, wood should read 20% or less moisture on a freshly resplit face?
 
(Curious) George said:
Isn't the rule of thumb that to burn easily and cleanly, wood should read 20% or less moisture on a freshly resplit face?
I understand that, but if you don't have that dry of wood/can't get to 20%, then you burn what you have.
 
I agree, it is not all Walnut, just wet walnut that is a problem. I am burning dry walnut now and a big split placed on hot coals shows flames in a couple of minutes (maybe less than one minute, I never timed it but it is pretty quick).

Splitting the wood smaller will help. Drying in the garage will help a little. I'd split it all smaller right now, stack is criss-crossed in a windy location and put something rigid over the top to keep the snow off. If you can get wind through the stacks the wood will dry a little even in cold weather. It won't be ideal anytime soon, but maybe better than it is now. Even if you can dry out just the surface, at least it will ignite a little faster.

I think the advice of others is good. Buy a few surplus/crooked boards from the discount rack at the local lumber yard, build a small stack in the stove and light them. If you get a nice start and hot fire, you can figure the set-up is fine and the wood is the problem. If you can't get kiln dried lumber to burn well, there is something wrong with the stove, flue, house, etc. I'd be cautious about building a big fire with 2x4s because they may take off faster than you expect.
 
KS-4-Life said:
(Curious) George said:
Isn't the rule of thumb that to burn easily and cleanly, wood should read 20% or less moisture on a freshly resplit face?
I understand that, but if you don't have that dry of wood/can't get to 20%, then you burn what you have.

Absolutely, just answering your original question.
 
(Curious) George said:
KS-4-Life said:
(Curious) George said:
Isn't the rule of thumb that to burn easily and cleanly, wood should read 20% or less moisture on a freshly resplit face?
I understand that, but if you don't have that dry of wood/can't get to 20%, then you burn what you have.

Absolutely, just answering your original question.

What moisture content is the wood you burn George?
 
So the way my insert is designed and installed, I have about 8" of the cooktop exposed in front of the faceplate surround deal. In other words, I have about a 26" x 8" flat surface that gets to 200-225 degrees. It doesn't get as hot as the stove because the way it was designed, the blower passes air between the stove body and the top "cooktop" surface.

I'm curious if I'll get some kickback on this idea.... I started laying some splits on the cooktop tonight, to try and speed up the drying process. I try to lay the flattest face down, to get as much contact as possible, to heat up the splits some, thinking I could help them dry out.

I did one piece for probably and hour and then threw it in the stove, and it seemed like it worked! I noticed that the end had more cracks or checks in it then before and I started thinking that I was onto something. So, I put 4-5 more pieces up there, again trying to get as much surface contact as possible. Again, after about an hour, I noticed all the splits starting getting small cracks all over the cut end, like checking from drying! I thought, woohoo I got something here!! BUT... then I split one of the pieces to test the moisture inside and sure enough, still read the same 31-32% that I keep seeing. Pretty much all my wood came from the same tree, so I'm thinking they are all going to be pretty close in moisture content.

And I thought I had solved the puzzle....
 
Status
Not open for further replies.