Glowing stove pipe

[cuttingedge]

So last night I had my stove (Jotul F55) cruising at about 650 and I noticed the stainless collar going into my flexible liner had a soft red glow. I have noticed this twice now. Is this something that I should be concerned with? Has anyone else noticed this happening? Am I running the stove too hard?
Thanks,
Jason

 

[edyit]

generally speaking glowing is too hot, what were you taking temp readings with? some magnetic thermometers can be off

 

[begreen]

Also, where was the reading being taken? And at what stage of the burn was this? Had the air control been closed down?

 

[AmbDrvr253]

Not enough information to answer the question me thinks........As stated it is generally NOT a good thing tho.

 

[cuttingedge]

It was right where my stainless liner enters the collar of the stove. It happened on a full load right after I turned the air to halfway. I know that red usually indicates too hot but my stovetop thermo was at 650 which I have reached numerous times before. The thermometer is placed on the cook plate on the back left side which is where the stovetop gets the hottest according to my Infared thermometer. This is also where JOTUL recommends putting the thermometer.

 

[blacktail]

Turn the air down sooner.

 

[branchburner]

I know that red usually indicates too hot but my stovetop thermo was at 650 which I have reached numerous times before. The thermometer is placed on the cook plate on the back left side which is where the stovetop gets the hottest according to my Infared thermometer..

If you have an IR gun, I would be frequently shooting other parts of the stove and flue to check their temps... a red glow means that part of the stove is pushing 900f, which is pretty hot. Also means the internal flue temps must be pretty high, too, if the external temp at the base of the flue is 900f.

 

[clark77]

You need to close down the air sooner. The flames were reaching the stainless pipe when you had it open all the way. I bet your stainless has discolored some now but it's ok. Instead of watching the temp, gauge your air reductions by how active the fire is inside the fire box. When the flames start getting crazy, back the air down to half. In another 10 minutes or so, back it down to a quarter then you could prob close down all the way after a few more minutes. It will all depend on how good your wood is as well.
As far as temp checking, this is the proper placement of thermometers.



With the thermometers in those spots, 700 is a good number to hover around. I don't like going higher than that but I have hit mid 700 a couple times. I made a high temp gauge to let me know how how it got over night. Just a bent up paper clip.



With the temps around 700 on the corners, the middle gets hotter. But I checked with jotul and that's all good.



Enjoy the stove, it will keep you warm.

 

[begreen]

Sometimes closing the air down in incremental steps is unnecessary. If the fire is burning strongly don't be afraid to try turning down the air all the way.

 

[Drayno]

I recently purchased a Regency i3100 insert and within the first two weeks or so of continuous burning have seen the liner start to glow on two separate occasions during start up so I closed the air and the glow immediately goes away. Stove top was at 250-300 each time. I have had the stove top out at 725 several times during a burn and never seen the glow, only during start up at low stove top temp. I have since stopped leaving the door cracked during start up and it hasn't happened since but now I am paranoid and constantly watching the liner. Collar and Liner have a copper/ light rainbow color which from what I've read seems to be normal. Frame of the stove has no cracks or sags. I have yet to put the surround panel on the stove and am afraid that If i had the panel on then I would have never noticed the liner glowing and could have caused real damage. I also currently have my only thermometer on the actual stove top near the liner which wouldn't be possible if I had the surround on. The wife really wants me to put the surround on but at this point I'm too nervous to do so. How do people with inserts go about this issue? IR Thermometer? Any thoughts would be appreciated..

 

[Woody Stover]

Any thoughts would be appreciated..

As mentioned above by clark77, watch the fire instead of the stove top meter, which reacts too slowly when you have the air open on a cold stove. You want a lively fire with some dancing flames, but not a roaring fire, which dumps too much heat up the flue.

You need to close down the air sooner. The flames were reaching the stainless pipe when you had it open all the way...When the flames start getting crazy, back the air down to half. In another 10 minutes or so, back it down to a quarter then you could prob close down all the way after a few more minutes./QUOTE]

 

[Mike.O]

Hi Guys.... going to bring this one back instead of another new thread....

Is burning less than ideal wood (30%) a contributor to high liner temps? My wood is less than ideal. I have been supplementing with 2 large Biobrick XL on top of each load and I am able to get good burns and i can fully close the air once the bricks catch. I have no smoke from the chimney after the normal 15 minute startup period. Get great temps up to 650 with damper fully closed. BUT.........

I've been fighting my liner heating and glowing WAY too quick. As in a minute of full load up and flames, the liner will glow about a foot up. The elbow and connector are not, but i have about 1" of corrugated pipe that I can see below the insulation and that glows. I have to be 100% attentive and sitting by the stove with my IR gun on each startup to manage the situation. As soon as the bricks catch and I damper down, everything is perfect and it cruises great for 12 hours. But the first 10-15 minutes of each load are a little unsettling...

My thought is..... the full load of less than ideal wood is producing TONS of wood gas. This gas is being ignited and burned by the burning biobricks. The ignition of the wood gas is taking place 1-2' up the liner instead of the firebox?

(Please no comments about burn seasoned wood. I know my wood isn't great and I have 10+ cords out back I have split from Oct. seasoning, but I'm trying to get through this winter as this second stove was not installed/planed until October)

 

[armanidog]

The moisture in the wood should actually cool the fire down. I bet the extra heat is due to the biobricks. Try using just one at the bottom of the wood to ignite it. It will dry the wood and the water will evaporate and keep the fire cool until the wood dries.

 

[velvetfoot]

I rigged up a setup with my HI300, which is a fancy Regency I2400, I put a thermocouple on the stove top near the flue exit. A controller turns the fan to High when it reaches a certain temperature, and then back to Low when it goes down. My stove only has two speeds. The fan definitely has an effect on stove temperature, but would be overwhelmed by too hot a fire. I use it to keep it a little quieter.

Anyway, the digital output of the temperature is quite nice. You can see exactly what's going on. I personally feel that stove top temp, near the exit is what you want to read rather than exhaust temp, which is more of a catalyst stove thing. Others disagree.

I would suggest some kind of digital thermometer with a thermocouple located at the place you think best. So much better than poking an infrared thermometer in the opening, or attempting to read a likely lame-ass bimetal thermometer in that same opening.

PS: With nice dancing flames, I shoot for 700, plus or minus 10, again, stove top, near flue exit. Stovetop temperature goes down of course over time.
PPS: To get those nice dancing flames, with tall chimney, I had to restrict incoming air flow. But that's another topic.

 

[begreen]

Hi Guys.... going to bring this one back instead of another new thread....

Is burning less than ideal wood (30%) a contributor to high liner temps? My wood is less than ideal. I have been supplementing with 2 large Biobrick XL on top of each load and I am able to get good burns and i can fully close the air once the bricks catch. I have no smoke from the chimney after the normal 15 minute startup period. Get great temps up to 650 with damper fully closed. BUT.........

I've been fighting my liner heating and glowing WAY too quick. As in a minute of full load up and flames, the liner will glow about a foot up. The elbow and connector are not, but i have about 1" of corrugated pipe that I can see below the insulation and that glows. I have to be 100% attentive and sitting by the stove with my IR gun on each startup to manage the situation. As soon as the bricks catch and I damper down, everything is perfect and it cruises great for 12 hours. But the first 10-15 minutes of each load are a little unsettling...

My thought is..... the full load of less than ideal wood is producing TONS of wood gas. This gas is being ignited and burned by the burning biobricks. The ignition of the wood gas is taking place 1-2' up the liner instead of the firebox?

(Please no comments about burn seasoned wood. I know my wood isn't great and I have 10+ cords out back I have split from Oct. seasoning, but I'm trying to get through this winter as this second stove was not installed/planed until October)

That sounds like a reasonable hypothesis. How wet is the wood?

If I waited for our stovetop on the T6 to get to 650º on a cold startup our flue temps would be over 1200º. Typically I am closing down the air at least 50% with a 400º probe flue temp. The stove top may only be 250º at this point. I pretty much ignore what the stove top is doing. This is why I think a good flue thermometer is more important than a stove top thermometer. Try closing down the air sooner. Turn it down as quickly as possible without totally squelching the fire.

 

[Mike.O]

That sounds like a reasonable hypothesis. How wet is the wood?

If I waited for our stovetop on the T6 to get to 650º on a cold startup our flue temps would be over 1200º. Typically I am closing down the air at least 50% with a 400º probe flue temp. The stove top may only be 250º at this point. I pretty much ignore what the stove top is doing. This is why I think a good flue thermometer is more important than a stove top thermometer. Try closing down the air sooner. Turn it down as quickly as possible without totally squelching the fire.

My red oak is around 30%, some sugar maple is a a bit less 28%-29%.

I would like a probe thermometer, but I have a less than ideal setup for a probe. I have my Summit stuffed in my fireplace. I top vent with insulated liner straight up the fireplace chimney. There is a 30* elbow at the base to help kick the stove out a little bit, but there is not any substantial pipe section 18" above the stove to put a good flue temp gauge. As of now, I have been just bending down and shooting with IR gun.

 

[begreen]

IR on the top of the elbow may be the best you can do. These will be surface temps, not probe, so you will have to adjust accordingly. With wood that damp it's going to be a challenge. Can you bring some in to sit in big plastic totes for a few weeks?

With dry wood these stoves are willing performers and get into secondary combustion pretty quickly. Your best bet is going to be to turn down the air as soon as possible until the flames get lazy.

 

[velvetfoot]

IR on the top of the elbow may be the best you can do. These will be surface temps, not probe, so you will have to adjust accordingly. With wood that damp it's going to be a challenge. Can you bring some in to sit in big plastic totes for a few weeks?

With dry wood these stoves are willing performers and get into secondary combustion pretty quickly. Your best bet is going to be to turn down the air as soon as possible until the flames get lazy.

I guess that's what I do too. I do not wait for the stove top to get to 700 before closing the door, primary lever, etc. I still think knowing the stove top temperature is important though, and that a permanently mounted digital thermometer is helpful.

 

[begreen]

With a well insulated firebox, the stove top will be quite a bit slower to come up to temp than secondary burn in the firebox. One needs to watch this or an overwhelming bloom of wood gas may not all get burnt in the firebox and instead burn above the baffle and possibly in the flue.

 

[brazilbl]

Sometimes closing the air down in incremental steps is unnecessary. If the fire is burning strongly don't be afraid to try turning down the air all the way.

Thank you for the postings giving advice on how to operate the air control lever. These little tidbits of advice are really helpful - Thanks!

 

[maple1]

My red oak is around 30%, some sugar maple is a a bit less 28%-29%.

I would like a probe thermometer, but I have a less than ideal setup for a probe. I have my Summit stuffed in my fireplace. I top vent with insulated liner straight up the fireplace chimney. There is a 30* elbow at the base to help kick the stove out a little bit, but there is not any substantial pipe section 18" above the stove to put a good flue temp gauge. As of now, I have been just bending down and shooting with IR gun.

View attachment 237743

Maybe a thermocouple probe + digital temp gauge?