Flue Temperature

[johnstra]

One big difference I've noticed between my new NC30 and my Mansfield is flue temperature.

Note that all I did was swap the stove - same flue, same stove pipe. I cleaned the chimney and cap when I did the stove swap.

I have a probe thermometer and with the Mansfield I could easily hit flue temps over 1000F. With the 30 I can't get it over 600. I don't understand why. The stove makes monster heat and it drafts well - it burns the way I expect it to in all ways except for this flue temperature discrepancy.

Anyone have any ideas why I'm seeing this?

 

[cmonSTART]

How old was the Mansfield. More efficient stoves typically have lower flue temps.

 

[Backwoods Savage]

Sounds like a good problem.

 

[oldspark]

How old was the Mansfield. More efficient stoves typically have lower flue temps.

That does hold true for my summit compared to my 30 year old Nashua, flue temps were much lower with the old stove.

 

[johnstra]

The Mansfield was brand new this past November (see my other thread on why I did the swap).

It's definitely a good thing when the secondaries are firing. I would think, though, that I should be able to get high flue temps when the primary is wide open.

 

[BrotherBart]

Since my 30 is in a fireplace without as much headroom as yours I don't have a thermo in the pipe. I did have a probe in the old elbow before I changed it and the liner out. It was three inches are so above the flu collar and the hottest I ever saw was 900 on start-up. Mine must get hot because the stainless elbow has been a golden color for a long time. I just don't get concerned about flue temps. All I need to know is told by looking through the glass and looking at the stove top thermo. And on occasion by stepping out the door and looking up at the chimney. I think flue thermometers were great when you couldn't see what was going on in your stove. Now I think they are in the buggy whip category.

Which is why my old stove didn't have one either. I have had glass in the doors of my stoves since 1985.

 

[cptoneleg]

The Mansfield was brand new this past November (see my other thread on why I did the swap).

It's definitely a good thing when the secondaries are firing. I would think, though, that I should be able to get high flue temps when the primary is wide open.

I'm going to look for your swap thread I would like to know, I don't run a flue thermo. just stove top.

 

[Wood Heat Stoves]

It's possible you have different wood with a different moisture content than before. This may not burn as hot with the stove wide open. Probably, though, it's just because the new stove is more restrictive and better at keeping the heat in the stove and not sending as much up the chimney. You may also have some creosote build up on your probe thermometer which is insulating it.

 

[johnstra]

I did clean the thermometer today. It did have some build-up on it. I used a 400-grit sandpaper to lightly scour off the crud. I'll see if that makes a difference. I'm burning the same wood now as I was before.

 

[Exmasonite]

What are the ambient temperatures? Could warmer weather be affecting your draft even though no change in liner/pipe/etc?

 

[johnstra]

It has been warm since I've begun burning in the 30. Ambient temps are mid 40s to mid 20s. So I suppose that could be a factor, but I don't think it's enough to account for the big difference.

 

[Seasoned Oak]

I get 600 stovetop and outside the single wall flue with a magnetic stove gauge so the inside temp must be higher.

 

[gdk84]

I will have to say, anyone believing a magnetic thermo will sure be mislead. With your standard Rutland type thermo, The hotter the temps the more off it is it seems. I was wondering my stove top temps at 675 with a half load. So, after a IR and surface probe temp unit to my suprise as the Rutland reached 650F it was about 100F hotter that both the other thermos. The less temp the less the difference. Im sure alot of people are aware of that but it can really throw you for a loop.

 

[Seasoned Oak]

I will have to say, anyone believing a magnetic thermo will sure be mislead. With your standard Rutland type thermo, The hotter the temps the more off it is it seems. I was wondering my stove top temps at 675 with a half load. So, after a IR and surface probe temp unit to my suprise as the Rutland reached 650F it was about 100F hotter that both the other thermos. The less temp the less the difference. Im sure alot of people are aware of that but it can really throw you for a loop.

It loses its magnetism at about 700 on the gauge ,so if i can find out at what temp the rutland loses magnetism ill know if its off and by how much.