In loving memory of Kenis D. Keathley 6/4/81 - 3/27/22 Loving father, husband, brother, friend and firewood hoarder Rest in peace, Dexterday

Temperature swings: Stove top & pipe

Discussion in 'Non-EPA Woodstoves and Fireplaces' started by Hoytman, Feb 6, 2019.

  1. Hoytman

    Hoytman

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    Wife wanted a fire last night and I waited a bit later than I really wanted to as I started the stove about 9pm.

    Non-EPA stove.

    35*F OAT and raining hard

    Got the STT of about 450*F (Magnet thermometers on stove top and one on pipe … plus an I.R. gun)

    Pipe to 350*F.

    I run it about 450* on the top all the time. I adjusted air down and slightly closed the damper about 1/4" movement was all. Left the room for a bit and came back and STT was almost at 600* and pipe temp was 500* and had begun to season the pipe a bit more … paint that is. This was the highest I've burned it and I don't like to get it that hot. I'm sure it didn't hurt anything, but out of my comfort zone … making the room uncomfortably hot as well as making me a bit nervous, so I dialed the air down to completely shut in order to drop the temps of everything and opened the damper all the way to let some heat escape. Walked away for about 3-5 minutes and came back.

    When I came back the STT was still at nearly 600* but the pipe temp had dropped completely below 300* … even dropping below 250* both on the magnetic thermometer and my I.R. gun … all with the air shut down and damper all the way open. Was sort of baffling to me why the stove top would keep reading so high and the pipe dropped so fast and especially so low.

    Had me wondering if my chimney wasn't clogged with creosote. Of course, I used a mirror to check the chimney before installing the pipe (8" x 8" square clay liner) and it was totally clear … totally. Stove had only been burned 4 times in 18 years before lighting it and I've only burned it about 12 days total this winter and those were in the last 2 weeks. That said, I don't see how a chimney could clog that quick, especially since most of the wood (3/4) of it has been seasoned for 3 years (ash).

    Just thought the entire ordeal was odd. I snuffed it out and everything cooled fine. Will open the stove tonight to see how much of the 4 pieces I put in actually burned. I'm wondering if all the wood was consumed with such a hot fire quicker than I expected. I'm hoping it's nearly gone when I check it this evening. If is, then I doubt if there's anything to worry about.

    Just wanted some input from other users on why or even how the pipe temp could have dropped that far and fast while STT being still nearly 600*.
     
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  2. brenndatomu

    brenndatomu

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    The STT stayed up because for whatever reason, super dry wood, wood species, the way it was stacked, chimney draft, phase of the moon, whatever, you had sustained secondary burn going on in your stove.
    You have just experienced what running an EPA stove is like everyday (with dry wood)...high STT and low pipe temps (when they are "cruising")
     
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  3. Eric VW

    Eric VW Moderator

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  4. Hoytman

    Hoytman

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    That's the odd thing … NON-epa stove … I did have 2 small splits of really dry ash in there but also 2 ash splits … same size nearly … that were some wetter with just a bit of water boiling out of the ends. That on a small bed of white oak kindlin coals. Sure, I realize if the stove gets hot enough you can get some secondary burn even in a non-epa stove (one with not CAT or tubes) but I didn't think it got that hot yet inside for that type of burn. I don't know. Interesting situation for sure and certainly didn't expect it.

    Even after I shut the air completely off and got the pipe temp to drop as well as the STT to drop to 400 all it took was one full turn on one side of the stove (other side fully closed) to bring the STT back to 500 and the pipe back to 400 … I shut it completely down after that because it was just too odd for me. I think I could have held that stove at 400-450 and the pipe at 300 easily on just a half a turn of one air intake. I didn't do that because I feared the chimney clogging for some reason even though I felt there could be no possible way of that happening with only 12 burning days and mostly 3 year seasoned wood.

    Hmmm...

    Will be interesting to see how much wood is left in the stove tonight after having shut everything down.
     
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  5. Eric VW

    Eric VW Moderator

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    I’d it possible you have an air leak somewhere?

    And I forget- what make of stove is this?
     
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  6. brenndatomu

    brenndatomu

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    I had that happen sometimes on my old non EPA wood furnace...the temps just went crazy, seemingly for no reason. Once I installed a peep hole/sight glass in the door, I could see what was happening...sustained secondary burn, even with low air settings. Heated the house really well when it happened, but the first few times I was freaking out trying to figure out why my plenum temps were so abnormally high, but everything else was perfectly normal!
     
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  7. TurboDiesel

    TurboDiesel

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    sounds like a more complete burn like you get with a cat stove.
    STT goes up, pipe temp goes down.
     
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  8. Hoytman

    Hoytman

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    Well, I never gave that much thought last night, but I think you're right after I've thought about it for a while.

    Now I won't say I don't have a gasket leaking … but I will tell you I just replaced them before lighting the stove this year and both doors dollar bill tested perfectly. That said, with an older stove and 2 doors the seem where the doors meet still likely leaks just a tad bit of air. I can't see anything with the room dark except for teeny tiny place at the tip of the door … I mean teeny tiny. I realize it doesn't take much, but I'm sure that isn't the cause because things started to cool down nicely just a few minutes after I shut the air supply down. If I opened it slightly the temps indicated it accordingly.

    Yeah, it had to be 2ndary burn inside the stove that kept those STT up and the pipe going down so fast. It was just odd.

    Nothing glowing red, but the further seasoning of the stove pipe did set off the fire alarm temporarily.

    It's the Solarwood wood stove that I started another thread about.

    My biggest concern was just how high would be too high for the STT and the pipe temps. I.R. gun read a tad over 400 on the pipe and 630 in one spot on the ST just for a few minutes. I know many here have newer modern epa stoves that often reach higher temps but I can't let this stove do that … it got to 80 real quick in the house and I'm sure I could have let it go well beyond that without the stove getting too much hotter … so I know I have way too much stove for my house … knew that when I started. This stove replaced the original stove my grandparents had and the house was to be auctioned off. I ended up with the house and my cousin got the original stove. This stove was his before he placed it in this house. If I'd have know at the time that I was going to buy the house I'd have kept the original stove built for my grandparents by my uncle. However, I wanted his son to have the stove his dad built for our grandparents, so it's all good.
     
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  9. Hoytman

    Hoytman

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    Yeah it does remind me of that … like the BK King model I looked at, except I didn't thing it should be happening or even could happen in an older stove. Those Kings will have pipe temps of less than 300 for long periods of time while the fire box is putting out, well the CAT, is putting out some good heat from the stove.
     
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  10. Hoytman

    Hoytman

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    One of you asked about the name...
    Solarwood.

    This stove has 3 convection tubes that come up through the fire box and I had two splits laying up against them pretty tight last night. I just about bet that had something do with the STT reading so high as well. I usually keep the wood from touching these, but last night I didn't … not sure it would matter much in a real hot fire anyway if it was touching or not … hot is hot.

    Here's my recent thread link.

    Solarwood wood stove

    Here's a picture similar to my stove.
    [​IMG]

    Yeah … that draft was barely closed and as soon as I opened it she started falling like a rock while STT remained steady, so I then closed the air intakes too. Interesting for sure.
     
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  11. Hoytman

    Hoytman

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    You wouldn't believe the hot air coming out of the top of the convection deck on days where the STT only get to 450*F … even with the blower off. The blower works, but I don't even use it because of the normal air flow it has. That coupled with my ceiling fan nearby on low and occasionally a box fan on low at the end of the living room blowing cold air from the bedrooms back to the stove … she purrs like a kitten.

    Last night with the STT that high the hot air was really being forced out into the room well.

    I'm going to check my chimney on Friday when it's sunny out, whether I need to or not, just be on the safe side.


    Last year I tried burning some ash that was too wet for about 4 hours. Glazed my stove all up inside, so I didn't even use the stove last year. So this year, after checking everything in the stove and up the chimney, replacing door gaskets I went and bought some of this Cre-Away Creosote Modifier - ChimneySaver to use just to remove the glassy glaze I put in this stove in just 4 hours last year. I'm sure the chimney got that way a bit too, that's one reason I got a little antsy last night, but I also knew the chimney was clear before I lit the stove this year.

    Been using this stuff regularly this year during the 9-12 days I've burned it. Probably isn't even necessary, but it can't hurt, and I'm hoping it will remove what little glazing I did to my chimney last year. It's already helped inside the stove.

    Just to reiterate … my clay liner before trying to burn that wet wood for 4 hours last season was like a brand new clay liner inside … clean as a new one. Again, aside from that 4 hour burn last year the chimeny hadn't been used in 18+ years.
     
    Last edited: Feb 6, 2019
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  12. Hoytman

    Hoytman

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    On a side note, I'd been thinking about modifying this stove with some 2ndary burn tubes. I'm not so sure I need to now. LOL!
     
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  13. brenndatomu

    brenndatomu

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    Getting last nights results regularly is the real trick...;) :binoculars:
     
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  14. Hoytman

    Hoytman

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    Yeah … I'm sure of that. Then again, it was a pretty creepy feeling and I'm not sure I want to duplicate it.
     
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  15. brenndatomu

    brenndatomu

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    Just because you didn't know what was going on...had you known, you would have probably been like "here, hold mah beer while I video this for my buds on FHC!" ;) :rofl: :lol:
     
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  16. TurboDiesel

    TurboDiesel

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    yes. you do.
    that perfect burn IS what you want all the time. and IMHO probably is what cleaned your chimney....
    not some (snake oil) chimney cleaner.
     
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  17. Hoytman

    Hoytman

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    Yeah … but it would have to been a Henry Weinhard's Rootbeer.:rofl: :lol:
     
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  18. Hoytman

    Hoytman

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    It didn't clean my chimney... it was already virtually clean except for that 4 hour burn the year before. Some minor glazing only a few feet up... stove fire box had it worse... but I'm sure it's all gone now. LOL!

    That could be. I've had some concerns about only running STT at 450-500 while pipe running much lower at less than 300. Which brings me to a question.

    For these stove top magnet thermometers … one on the stove … one on the pipe … which one do I pay attention to … that is … which one is most important regarding having the needle in the correct burn zone?

    From what I've read the surface temps are about half of what the inside temps are … there abouts.

    I've used a wood stove quite a bit without any issues in years past … but always without a magnet thermometer … and I realize a probe therm is best. I should have used any thermometer years ago, just never bought one.
     
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  19. brenndatomu

    brenndatomu

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    Sounds good to me! :yes:
     
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  20. TurboDiesel

    TurboDiesel

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    any creosote cleaning in your set-up was probably a result of a good hot fire.

    those mag therms are notoriously inaccurate, but id try to hit 450-550 on the stove top and about 250-300 on the flue pipe about 12-18" above the stove outlet:yes:
     
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