CAT Thermometer

[Murray01]

Pictures are of the end of the CAT Thermometer. Appears to be delaminating.

Is this normal? Warranty?

First fire was October 2025, burnt about 3 cords of Jack Pine in a new stove.

 

[stoveliker]

Makes me wonder how your flue looks like, given the shiny stuff.

Some delamination from oxidation I see too. I would brush that off with a steel brush as it hinders thermal transport to the core of the rod which transports it to the bimetal coil at the viewing end.

 

[Murray01]

Makes me wonder how your flue looks like, given the shiny stuff.

Some delamination from oxidation I see too. I would brush that off with a steel brush as it hinders thermal transport to the core of the rod which transports it to the bimetal coil at the viewing end.

The picture is after I brushed it off with a wire brush. The shine is from the light coming in a window, out of the light it’s dull.

 

[stoveliker]

Okay.
I've had similar delamination of outer layers. I think oxidation and thermal expansion differences cause this.
I brush it more rigorously than you have done.
I'm not sure how important it is, but one doesn't want to hinder the core of the rod warming up due to loose layers on the outside that shield the core.

 

[Murray01]

Okay.
I've had similar delamination of outer layers. I think oxidation and thermal expansion differences cause this.
I brush it more rigorously than you have done.
I'm not sure how important it is, but one doesn't want to hinder the core of the rod warming up due to loose layers on the outside that shield the core.

If I brush it rigorously then I’m guessing the core or part of it will be exposed. So far I’ve only brushed the loose oxidation particles off.

 

[stoveliker]

The core is solid metal (copper I think) so that's not a big deal once the outer coating is compromised already.

That second pic clearly shows a poorly adhering layer. That should come off imo as it'll hinder thermal contact of the absorbing outer layer to the core that transports.it to the coil.

Maybe others have different opinions?

 

[Murray01]

One other point I just remembered, during a cold snap I did notice that the CAT thermometer needle was pinned to the 7:00 o’clock position, almost to the “Inactive” zone after a hot reload an letting the stove run for 20 minutes with maximum air flow. Since that time when I let the stove run with the thermostat turned to maximum the needle will climb to the 7:00 o’clock position, previously the needle would max out at about the 5:30ish position. I’d guess that’s when the outer protective started to crack and deteriorate.

I let the stove cool down yesterday to clean ashes, the needle did fall back into the inactive zone as per the owner’s manual.

 

[Highbeam]

I've gone through a BK cat meter and currently have a well used condar cat meter. Both have had this outer layer peel off. It's weird but I have it happen too. I don't peel it off but try and keep it small enough to not get stuck in the stove.

 

[Murray01]

Got a bit more aggressive with the brushing, a few more small flakes came off. The picture below is the highest I’ve seen my CAT thermometer go. Appears to be more sensitive to heat with more of the core exposed.

 

[stoveliker]

But does it go to the lower edge of the inactive zone of it gets back to room temperature?

 

[Murray01]

Yes. Works exactly as it should.

Just way more sensitive and more movement on the dial than the previous Princess I owned.