This is the second winter in a row that my barn water, frost free, hydrant has frozen up on me. Need to wait till it thaws out to fix, but figure now is the time to get some help and make my plans. Hydrant drain hole is 6' down. This year due to early snow cover that stayed, the frost is only 12-36" down. Before it froze up, both years, the colder it was, the harder it was to pull the handle up. This would change based on the outside air temp rather than getting harder as the ground cooled off. I have a large drain field down there, but it is in heavy clay. I have two thoughts. One is that the drain field is filling up, but at the depth it is at, even with the clay it should not freeze up like that. The other thought I have is that the rubber plunger at the bottom of the hydrant is shot and leaking a bit. Cold air moves in and flows down the pipe, freezing it into position. Before it froze up, I would pull hard on it to get it open, but once I was done and tuned it off, it would slide easy, as though the water passing though it thawed out any built up ice. What other ideas or causes could it be? As always, thanks.