Flue temps different than stove top???

[Nyminitrucker]

Hello everyone. I'm new here and it's only my second post. I have a Mansfield model 2011. My setup is as follows:
- stove is located in a corner ( all clearances are met and they are the required minimum)
- six feet of single walls black 6" stove pipe to the "thimble" thought the roof
- about another 6 feet of double wall pipe from there.
- hearth stone rear heat shield with fan installed

Now my problem ( maybe its not a problem and its perfectly normal) is that the stove temp and the flue temp are at a 200 degree difference. The stove top temp reads about 400 (stone guard brand thermometer) and the flue temp reads 200 degrees ( Rutland magenetic type). The air primary air control when this happens is all the way chit with the secondaries going good.

Is this normal to happen? Thanks.

 

[Butcher]

Yep.

 

[Todd 2]

It is normal to have a hotter stove than flue temp, lets you know that all the heat is not going up the chimney when your secondaries are active, however if you can IR gun the thermometer locations to be sure they are accurate is a big + some of the coil rap/ magnetic thermometers can read way off. Accurate known temps gives you positive peace of mind control with your stove Todd

 

[begreen]

If this is single wall pipe, you are reading surface temps with the thermometer. The actual flue gas temps are somewhere around 1.5 to 2X hotter.

12' is a short chimney, with a lot of heat loss from the single-wall. How well is the stove burning?

 

[Highbeam]

Your flue gas temps are the same as your stove top temps. The outside of single wall is only half as hot as the inside. So 400 all around. Actually pretty cool flue gas temps for a hearthstone. I burned a current model Hearthstone heritage for 25 cords with a real probe meter to measure actual flue gas temps and the flue gasses were always hotter than the stove top, often more than twice as hot. A huge waste of heat up the stack.

These days with a higher efficiency stove, the flue gas temps run at 400 when the stove top is at 600. I can hold my hand on the outside of the double wall black inside pipe when flue gas temps are this cool.

 

[PLAYS WITH FIRE]

So bg, I asked this question in another thread and no one answered. If take readings with a laser from my flex pipe from my insert, which is is basically single wall, the temps from the outside are 1.5 to 2 times higher inside?

 

[begreen]

So bg, I asked this question in another thread and no one answered. If take readings with a laser from my flex pipe from my insert, which is is basically single wall, the temps from the outside are 1.5 to 2 times higher inside?

It's an estimate for 24 ga single-wall 18" above the stove top. I don't know about flex. Flex liner is pretty thin so I'm not sure how that would correlate to surface temps without instrumenting. Surface thermometers are typically placed 12-18" above the stove top, yet I suspect you are reading just above the flue collar. I would think that in combination with the thin flex that area would read hotter and closer to stove top temperature.

What temps are you reading on your flex?

 

[corey21]

Sound fine to me you flue gas is about 400 i think.

 

[Nyminitrucker]

I will go out tomorrow and get an IR thermometer so I can be sure. So generally the actual temp of the flue gas is about 1.5-2x hotter than the outside reading so I'm fine then. I will post my results with the Ir when I get them.

 

[Highbeam]

When I would load up the heritage for the night and get a good secondary rolling, stovetop would set at 450 and real interior flue temp at 800 for a long long time. Daily, I would run the flue gas temps up over 1000 to keep her clean. That stove sent so much heat up the stack it was embarrasing. The mansfield at 400 sounds much better.

 

[corey21]

When I would load up the heritage for the night and get a good secondary rolling, stovetop would set at 450 and real interior flue temp at 800 for a long long time. Daily, I would run the flue gas temps up over 1000 to keep her clean. That stove sent so much heat up the stack it was embarrasing. The mansfield at 400 sounds much better.

My flue gas runs at 400 i have left the air open to long before and it hit 800.