Sec. Triflora rhododendron such as Rhododendron augustinii. If you go walk around the Rhododendron Species Botanical Garden while yours is in flower you may encounter same or similar there, with labeling. If you decide to do this snip a flowering sample twig, put it in a small portable container with water in the base, to keep your specimen hydrated and take it with you. So you can hold it next to similar plants at the garden to see if they are exactly the same as yours.

http://rhodygarden.org/cms/

I was never keen on Rhodies either until we bought our house. Nice to have some mature plantings and can't beat the colour in Spring! They take well to pruning in my experience. I have to do mine regularly as they are too close to the house.