I just moved into a house. I have a 50 amp max tankless water heater. The circuit breaker is 50 amps. The water heater is connected to a NEMA 10-50 power receptacle. There a switch to turn on and off the water heater from inside the house. I am going to replace the switch. I noticed that it is a double pole 30 amp switch.
I haven't tested the water heater yet and I am going to replace the switch, but I would like to know if this is a safe setup, since the switch's amperage is lower than the water heater's max.
Best Answer
I am going to try to brake down your question.
Now just off of what you said the 2014 NEC Table 310.15(B)(16) shows that a #6 or #4 wire is needed for 60 amps, depending on which wire you use.
You are right in line with the amps of the water-heater.
That receptacle is only rated up to 50amp but try to find a 60amp 3wire receptacle.
BIG problem, the switch is way under sized, but from your picture it doesn't look like the correct size wire ether.
I would look at the wiring that is going to the breaker and see if it is correct. You may have to start over again.