How to measure temps with an insulated chimney

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mpaul

Burning Hunk
Hi everyone. I have a 42 Apex that has a 7” insulated chimney. Reading all the posts here I’m learning the best method to measure and monitor performance of your fireplace is through chimney temperatures. However, all the posts I read talk about single or double walled chimney, not insulated chimney’s.
My thought is to get a probe based thermometer to insert into the chimney. My concern is drilling a hole for the probe through the insulation. Are there any concerns with doing this?
My unit came with a pretty sleek in wall digital thermocouple that measures the temp of my cat. It’s impressive to watch and see the temps get into 800-900 degrees. Reading about cats though I see the temps can go so much higher without damage. Still if I see that cat get into 1000 degrees I panic and dial the unit way down.
I have an access panel to one side of the unit. This would allow me to insert the probe into the chimney. I really am looking for a system that will give me an audible alarm if my chimney temps go too high especially during overnight burns. Any thoughts? Thanks.
 
Yep. It is a 7” insulated chimney that hooks directly to the stove. It’s a zero clearance fireplace inside a chase so the chimney is insulated.
 
The instructions probably were meant for a non-cat stove. For a cat stove go by the cat temperature. You shouldn't drill into insulated chimney pipe.
 
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Got it. Thanks begreen. I usually run the cat temp between 800-900 degrees. I’ve read that damage occurs at 1500. Am ok running at 1000-1100?
 
Yes, it's ok to run between 800-1400º.