johnd24: You state that the H2O heater is on a geothermal sys. The accepted method with geo is two H2O’s, not one large one. The H2O’s are connected in series with the first H2O connected to the geo preheat with NO ELECTRIC CONNECTION to the unit. The second H2O is connected to power. My system has two 42 gallon H2O’s connected as indicated on system one and a 30 gallon storage only on system 2. Rowdy
I have just installed a John Wood 5500 watt water heater. It runs non-simultaneous operation, only one heater at any time. The owner manual for this electric water heater recommended a 35 amp fuses or circuit breaker for 208 or 240volts. Now the question? #8 wire with a 35amp breaker. If you calulate the load a 30amp breaker with #10 wire should work but the manufacturer recommeded 35amps.
