Hi
As a complete novice here will try not to break any rules.
I currently have the heater/air-conditioner matrix on the bench. Getting access to it is a big job.Thanks to Guillaume for the excellent notes.
There are two negative temperature coefficient thermistors in there that would need dismantaling the matrix to replace. My thought is to duplicate the sensors. The ones with the pretty green logo cost an obscene amount with the specialist retailers still causing plenty of pain with N.O.S. Has anybody found a source of reasonably priced alternatives or am I wasting both our time?