Taco Flo-Chek - 1" Sweat Dripping

I have a FHW Boiler with a 1" Sweat Brass Taco Flo-Chek at the beginning of a split zone running heat to the bedrooms. The valve started dripping last year, but only to the point where it's a 2-3 inch round wet spot on the concrete. I've never seen it drip only know because of the wet spot. Is this something to be concerned with or can I just leave it to drip until or if I notice a more substantial amount of water? Thanks