Once water runs through a typical faucet in the winter, the water that remains in the line freezes. It’ll stay frozen until temperatures warm enough to thaw it meaning you’ll have to find a secondary source of water to fill buckets. A simple change solves the problem.
A frost-free hydrant works in much the same way as a faucet. The handle goes up, water flows; when the handle is down the water stops. But what keeps these hydrants from freezing? The on-off valve is buried underground beneath the frost line. When the hydrant is turned off, a drain hole in the underground valve opens to release any remaining water from the hydrant’s standing pipe into the unfrozen ground to clear the pipe and prevent freezing. The level of the frost line varies depending on the climate in which you live, so make sure it is installed to the appropriate depth.
The shut-off valve is positioned 8-12 inches inside a long stem (the sill cock pipe) so that the water drains out of the stem and only remains inside the building to which the faucet is attached. A sill cock pipe is one that runs from the indoor shut-off valve to the outdoor faucet. The longer the sill cock that resides within heated or insulated walls, the better protected the water line to the faucet.
The sill cock drains to a small hole called a petcock so it empties itself of water when the faucet is turned off. In modern frost-free faucets, there is no backflow of water into the water source, but rather drainage from the sill cock goes elsewhere.
In plumbing jargon, a frost-free faucet is also referred to as a hose bib or an anti-siphon freezeless yard hydrant. To make these work most efficiently, it is always smart to disconnect hoses from the faucet once you are finished using the water. Then, water can drain through the petcock and clear the exposed line of water that would otherwise freeze.
If your water faucets are not of the frost-free variety, it is important to clear the lines before winter. Any water that remains in the pipes could freeze and rupture a pipe. First, you’ll need to turn off the water supply to the outside faucets, then open up each faucet handle to drain any remaining water. Leave the handle open through the winter. If the weather in your area becomes colder than your norm, you can apply heat tape to the exposed pipe of your frost-free hydrant. This will give you additional insurance for having running water.
By Nancy S. Loving, DVM