replying to ARW, GeoffB wrote:
Thanks for your reply.
Do you mean that there is some sort of connection between the HW and CH
switches inside the programmer? If so, then your explanation begins to make
some sense. For the case you describe, if the CH switch is still live, owing
to 'back feeding' from the live HW switch, then the CH valve would stay open.
But how does 'back feeding' work?


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