Ask 'Dr. Spa' Q & A Message Board

No. Two #12's do not have the ampacity of a single #6. You would be much wiser to run the proper #6. The single, larger conductor is much safer. I understand that you do not need to meet US Code, which in turn is fashioned after internationally recognized code, however it is definitely in your best interests to do so. First, it will ensure a safe installation. Remember, we are mixing water and electricity here. Second, it will preserve your warranty rights, assuming that this is a new tub. Parallel circuits are not appropriate for this application. You would literally need three #12's in place of each required #6. Assuming you are using a three wire plus ground circuit, you would literally need twelve #12's. The problem with that is two-fold. Your conduit fill ratio will likely be extraordinarily high and issues such as hysteresis and overheating will further degrade the circuit.

John

: I have seen parallel conductors on heater circuits a number of times,