I have two frost free anti-saiphon multi turn sillcocks one on the north side and one on the south side of the house. I can not get any water from either of them this spring. The pipes are not frozen and there are no seperate shut-offs for these sillcocks. Does anyone have any ideas how to fix this issue? 12-in L x 1/2-in MNPT Brass Anti-Siphon Multi Turn Sillcock The link shows an example of what I have.