I have an Itasca 36F that has 2 bath rooms. Love the floor plan but I have a problem. The small mid coach bath room has a terrible odor as does the compartment below where the black tank pump is locat...
Be sure to check your battery fluids to rule them out of the problem. When they get boiled out of fluids by being over-charged by 13.6VDC for long extended times it smells like rotten eggs to me...