Electric water heater... bad neutral
Hi my name is ron, here is my problem a few weeks ago our outside main shutoff went bad,I replaced it and now have another problem, every time I turn the breaker to my water heater on I hear a buzzing noise,the lights get bright and then the breaker trips.once the breaker trips all is back to normal.everything in the house still works no light flickers all other 220v appliances( stove,dryer etc... )still work fine with no light dims upon turning them on and no other problems in the house.I was told by a friend that this a bad neutral.how do I test? Our homeonly has a 100 amp service as a trailer used to sit here and the service was never switched they just tied into the old trailer lines thanks for any help ron