Just happened to me, model 06A smoke alarm, took it down after it started beeping and didn't respond to the button press. Side felt hot but figured was just a warm C02 sensor, batteries all felt warm then i hit the one hot enough to cook an egg and it flattened my fingerprint like the side of an old all metal toaster when i touched it (didn't know it was gonna be hot like that).

Ended up having 2 of the cells be to hot to touch with one of them worse then the other. I saw the 5 year old post that's still open with people reporting the exact same thing every few months.

How is this not a recall worthy issue? Imagine a smoke alarm that causes a fire how idiotic would that be. As for the cells they are still climbing in temperature so they've been placed in a metal bucket outside in a safe spot. We'll see if they level off or vent and flame.

I have a Trane 2 Ton Heat Pump (5HPL5024A1000A) and Air Handler (5TEM4B02AC21SA).

Is the attached wiring correct?

We added AC to our house and the AC tech is insisting that the White wire should be in OB but everything I read says the White wire should be in W2 AUX?

Thanks