Hydrangeas are most likely to have no blooms if they were pruned incorrectly, if cold weather damaged the buds or if they have a lack of sun. The white variety in flower tells me your pink hydrangea does get enough sun and if you did not prune it last year then I suspect cold winter weather froze the buds. Some hydrangeas such as the mountain hydrangeas and the smooth hydrangeas are very cold tolerant and these come in white forms. The winter tender hydrangeas are the big leaf hydrangeas that come in pink or blue depending on the soil. This winter try piling on a deep mulch of at least 12 inches tall  at the base of the plant after the leaves have fallen off. Be sure to remove the mulch in spring when you see new leaves emerging. The mulch may keep the roots warm enough to save the flower buds. You could also try moving the disappointing pink hydrangea to a new location where it will be more protected. A spot with morning sun and afternoon shade would be ideal for a big leaf hydrangea. Keep growing, Marianne Binetti