I know that if overloaded, circuit breakers will trip, so I was adamant when the wiring was done for our addition, that there wouldn't be an issue in the equipment room for the big tank. The guy who wired everything and set up the generator told me that 20 KW would not power the whole house
A couple of months ago, I discovered I have eight 20 amp circuit breakers for the equipment room. talk about overkill. No wonder the old part of the house couldn't be on the generator system.
Right now, I have extension cords plugged into outlets on the generator system going to the current little tank. Really is piece of mind knowing that it will be business as usual during any power outage, whether we are home or away. Sometimes I wake up to the sudden silence only to hear the generator kicking on. It just makes life so much easier.