New Zero Clearance Install—question about installing probe thermometer in Class A Chimney

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reforminded

New Member
Nov 29, 2021
13
Connecticut
Howdy folks—I just finished rough install and passed inspection for a new Pacific Energy FP30 Zero Clearance fireplace. This thing is a beast, and even the moderate break in fire was throwing significant radiant heat (blowers aren’t hooked up yet) so I am very excited for what she will be able to do.

We installed it with stainless Class A insulated chimney from the stove up to the sky. Before I close up the wall with cement board, I would like to install an Auber probe thermometer so I can get accurate flue temps. Obviously once the wall is closed there will be no way to add this. Everything I am reading here talks about people installing the probe into double wall “stove pipes”, that connect to chimneys. On my basement stove our stove pipe is much smaller and thinner than this chimney, so I assuming people are talking about that kind of setup vs a class A. So my question is, can I install a probe thermometer into a Class A chimney? Is it too thick for the probe to go deep enough for readings? Will it damage the chimney? Any advice is appreciated.
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Cutting a hole in class A should not be done, imo. It affects the insulation value of the pipe, and thus its safety rating.
 
I think that should be okay. It's a more permanent hole though, in a.part of the appliance rather than in the pipe.

Your temperature readings would be less comparable to others, but it would still function well for managing your own burns once you figure out what readings give.tje best results.
 
I think that should be okay. It's a more permanent hole though, in a.part of the appliance rather than in the pipe.

Your temperature readings would be less comparable to others, but it would still function well for managing your own burns once you figure out what readings give.tje best results.
Just got off the phone with a tech rep from Pacific Energy (A+ customer service FWIW, answered all my questions patiently and expertly). He said we could drill into the flue collar, but that his concern was that any probe has a finite life span due to them being constructed of different metals welded together, and that over time with thermal expansion they will eventually fail. He said we could get 5 years, could get 20 years, but that at some point we would be opening the wall back up to replace. Given how easy it is to burn this stove (and it really is easy, with their "Extended Burn Technology" it is almost impossible to turn the air down too much and smolder) he suggested that as long as I am careful about not intentionally over firing by overloading and leaving the damper all the way open (a problem any stove would have) he didn't think I needed to worry as much as I am and he would forgo the thermometer. He said in their lab testing they use Omega brand probes, which he said are good, but they need to replace them every year.

Long story short, they said flue collar would be OK, but ultimately don't think it is necessary.
 
Sounds fair enough.

If no issues arise, you will be fine. If issues do arise, a probe would help identify causes.
It is not a strict necessity, but a nice thing to burn as efficient and safe as you can, and to solve problems if they arise.
 
Just got off the phone with a tech rep from Pacific Energy (A+ customer service FWIW, answered all my questions patiently and expertly). He said we could drill into the flue collar, but that his concern was that any probe has a finite life span due to them being constructed of different metals welded together, and that over time with thermal expansion they will eventually fail. He said we could get 5 years, could get 20 years, but that at some point we would be opening the wall back up to replace. Given how easy it is to burn this stove (and it really is easy, with their "Extended Burn Technology" it is almost impossible to turn the air down too much and smolder) he suggested that as long as I am careful about not intentionally over firing by overloading and leaving the damper all the way open (a problem any stove would have) he didn't think I needed to worry as much as I am and he would forgo the thermometer. He said in their lab testing they use Omega brand probes, which he said are good, but they need to replace them every year.

Long story short, they said flue collar would be OK, but ultimately don't think it is necessary.
Did you end up installing one?