Pentair Minimax 250 heater with pump controlled by an external timer. I am trying to figure how to turn off the heater using an external switch to power down the heater 20 mins before the pump shuts off. My problem is that I am looking for a circuit in the heater that could serve this purpose.
The "professional" that installed the heater used the wiring to the thermal fuse as the circuit to turn off the heater. So when the timer shuts off, the heater "thinks" the thermal fuse is blown and shuts off the gas. Problem is that this triggers one of the safety mechanisms of the heater; it WILL NOT restart the next cycle, displays "ERR" and "call technician". I have to switch the unit off then on again to reset the system. It works fine until this happens again.
So I call Pentair and they instruct me to use the "Common" and "Pool" terminals on the circuit-board for this purpose. But there was no jumper between these two terminals. When I connect them with alligator clips, it makes no difference how the heater functions, including the fatal error described above.
Any ideas where to wire this properly?