so the control on the bathroom wall heater is apparently stripped...

[TreasonousBastard]

4. If you are lucky, this is a very simple fix...

But, not having seen the controls or the heater, I can't guarantee that.

First, see if you can pull off the knob and see if the plastic ribbing inside is stripped. If it is and you can still turn the metal stub by hand, and it works, just get to a hardware store and buy a new knob.

If, however, that metal stub slips around not doing anything, or is stuck, you probably have to replace the whole assembly. Or more.

Usually, there are relays and resistors built into these things, and some even have proprietary chips and software. (I once tried to fix a vacuum cleaner that had a "digital control module" instead of a simple on/off switch. Yikes!)

At this point, you might want to get in touch with the manufacturer for help. And you might end up calling an electrician or recommended repair guy to do the job. And don't be surprised if just installing a new one makes more sense than fixing the old one. A new one might be similar labor cost, and have a warranty and be more electrically efficient than the old one.

As long as the breaker is off, you won't get electrocuted playing around with the thing. But, any time you play with electricity you have the (admittedly small) chance of fire when you turn the breaker back on.

Good luck.