I'm replacing my old 15 KW electric furnace in my mobile home with a new 12 KW model. In checking out the wiring instructions, I note that the 15 KW needs a 90 amp circuit breaker, while the 12 KW only needs 70 amps. Also, the wiring requirements are different. I currently have a 90 amp one installed, along with the larger size wiring (2 pole). Is there any problem using my current circuit breaker and/or wiring?