Little run away issue

  • 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.

Welderman85

Feeling the Heat
Nov 1, 2017
294
Chesaning MI
It was a little chilly this morning so i lit a fire in my insert. I have a thin wall flex liner. I opened the air lit the fire then go distracted. I came back to a hot flue temp. I keep it under 400 on the line and it hit a little over 500. Will that do any damage to my liner. Thank you
 

jetsam

Minister of Fire
Dec 12, 2015
5,257
Long Island, NY
youtu.be
Short answer, no.

Long answer, you may have other issues. Please describe where and how you are measuring flue temps (this is typically not possible on an insert).
 

Welderman85

Feeling the Heat
Nov 1, 2017
294
Chesaning MI
I took the top surround panel thing off and use a temp gun. I checked it about 10" up from the stove
 

begreen

Mooderator
Staff member
Nov 18, 2005
87,751
South Puget Sound, WA
The liner should be ok. A temperature of 1000º for a short duration is within tolerance. We all get distracted at one time or another. It's a good idea to set a timer if not staying with the stove during startup. A cellphone timer works for me.
 

jetsam

Minister of Fire
Dec 12, 2015
5,257
Long Island, NY
youtu.be
A few thoughts-

IR guns typically read low on shiny things.

Surface temperatures on a flue are not a really great way to determine internal temperatures. Internal temperatures may be double what you see there.

Between those two factors, you could have been running too hot there- with some pessimistic assumptions, if the IR said 500, and it was really 600 on the surface, internal temps could have been 1200+. (Or they could have been significantly lower.)

The normal way to nail it down is a flue probe thermometer, but I would not personally put one in thin wall liner unless it was mechanically secured to something else and putting zero pressure on the liner that could tear it over time.

You could make your IR gun a little more accurate by hitting the liner with black stove paint in the spot where you measure it.

None of this is strictly necessary- most insert owners don't have any visibility of their flue temps.
 

bholler

Chimney sweep
Staff member
Jan 14, 2014
24,217
central pa
It was a little chilly this morning so i lit a fire in my insert. I have a thin wall flex liner. I opened the air lit the fire then go distracted. I came back to a hot flue temp. I keep it under 400 on the line and it hit a little over 500. Will that do any damage to my liner. Thank you
It's fine. Your internal temps were probably about 1000 but your liner is rated to 2100 for short periods. At the temps you had you won't hurt the liner. Running at those temps regularly will hurt the stove eventually though