> If all you need to do is replace a potentiometer with electronic control, it may be possible to do that with a vactrol. It's more invasive perhaps, but then w

> If all you need to do is replace a potentiometer with electronic control, it may be possible to do that with a vactrol. It's more invasive perhaps, but then we're not dealing with anything mechanical. This is what I was wondering about as well. The knobs on the unit are probably potentiometers, so it ought to be possible to replace them with a digital device of some kind, and avoid the mechanical coupling altogether. I imagine that the author did consider this possibility, but decided that disassembling the control panel in order to replace or byypass them was just too difficult and dangerous, especially since everything is at AC line voltage as he notes in the write-up. The modern smart thermostats that I've looked inside have a clean separate between the low-voltage digital side, and the AC-line-voltage power control side… but evidently these older purely-analog devices didn't.