Turning Bolt off.

Aero Hot Water Heater w/ Oil Beckett Burner, need take bolt off top of tank, the top cap. This is to vaccuum sut out, cannot. The bolt does not come off. I turn it counterclock and even hammered the appropriate wrench and will not moe. Is counterclockwise correct?

If what you are attempting to do is not spelled out in the owners manual as end user maintenance, stop what you are doing. I am unaware of any water heater manufacturer who advises end users to remove plugs from the tank in order to flush the tank.