At Mark Jr Plumbing & Heating Inc, we provide fast, reliable & guaranteed service for all of your plumbing, heating, air conditioning and oil to gas conversion needs. Superior & customized residential & commercial service for over 18 years.At Mark Jr Plumbing & Heating Inc, we provide fast, reliable & guaranteed service for all of your plumbing, heating, air conditioning and oil to gas conversion needs. Superior & customized residential & commercial service for over 18 years.