I was getting this warning message in klipper: "Heater heater_bed not heating at expected rate. See the 'verify_heater' section in docs/Config_Reference.md for the parameters that control this check."
After some investigation I found that at almost exactly 115C my heatbed would just stop heating. I'd watch the graph and it'd climb to 115C, then slowly cool off.. even though the 'power applied' was showing as 60 (my max_power setting in printer.cfg).
Turns out that either this particular 125C part cuts off at 115C, or my heatbed thermistor (Kenevo heating pad) is off by ~10C. I don't have a good way to test the temps right now so am not sure which. I have another Voron 2.4 350 with the exact same part and it goes to 115C no problem and has for over a hear.
The good news is that it's a cut off, not a regular 'fuse' that 'blows.' It just cuts out the power and once things cool down and a new heat cycle starts I can get back to ~112C w/o any cut off / replacing the part. I like printing ABS on the Voron 2.4 350 at 115C so am going to swap out with another 125C thermal cut off, and if that doesn't work will buy a 135C cut off from aliexpress (west3D is out of stock on the 150C version and I don't need to go that high).