Around 18 gauge is best.Do you know what gauge the wires are?
Those wires being seperated I assume would not allow power to the heater. Is this correct?
The Jandy pool control panel is about 9-10' from the heater.Post the heater make and model.
Also post how far the automation is from the heater.
Then this is correct:The Jandy pool control panel is about 9-10' from the heater.
The MasterTemp Installation Manual specifies using 18 gauge wire with a minimum 3/64” (1.2mm) thick insulation rated for a temperature rise of at least 105°C.