Winter weather doesn’t come often in the Houston area, but when it does come, make sure you are prepared. One question we get asked often is, “How do we prepare our sprinkler system for a hard freeze?”
Most homes in the Katy area have a backflow preventer installed where the on/off switch controlling the drinking water supply is connected. The backflow preventer, aka pressure vacuum breaker, is a key component needed to prevent water contamination, but they are vulnerable to freezing and usually blow after a hard freeze starts to thaw.
Let’s walk through the steps you can take to prevent blowing your backflow preventer. Click on the image diagrams below for helpful tips and visual illustrations.
Steps to Drain the Backflow Preventer Before a Hard Freeze
1. Turn the lower manual valve clockwise so that it’s perpendicular to the pipe (the one in the image above is still in the on position).
Turn all upper valves clockwise so they are perpendicular to the pipe they are connected to. Sometimes they are very hard to move and may require pliers to turn.
Get a flathead screwdriver and open the screws to let the water out. You only need to turn the screws about 45 degrees to let the water out. There may be only a small amount of water, but water expands when it freezes. Remove any water inside the pipes to drain out, and stop the bell-shaped preventer on top from popping off from increased pressure during a hard freeze.
That’s it. Your irrigation system is winterized.
If you don’t plan on turning on your sprinklers after the freeze you can leave the backflow preventers open. However, if you do plan to use your automatic sprinklers make sure you turn them back to the closed position before they run to prevent drinking water contamination.
Important Caveats
Not all backflow preventers are the same; yours may look a little different. This is the general setup of what you might see outside your home.
If you have an older home you may not have a shutoff valve or the ability to drain water from the backflow preventer. If that’s the case, do not touch any of the valves. Instead, we recommend wrapping it in thick insulation in an attempt to protect it from blowing in the freeze.
