Texas winters are usually mild, but it only takes one hard freeze to crack a sprinkler pipe, split a backflow preventer and leave you with an expensive repair when spring arrives. The good news is that winterizing a sprinkler system in Texas is simpler than it is up north. This guide walks through when to do it, step by step how to protect your system, and how to bring it back online safely after the cold passes.
Why winterizing is different in Texas
In northern states, the ground freezes deep for months at a time, so sprinkler systems are fully drained or blown out with compressed air every fall. In Northeast Texas, the ground rarely freezes deep enough to damage buried lines. The real danger is sudden cold snaps, when temperatures drop into the 20s overnight with little warning.
That means the parts of your system that sit above ground or close to the surface are the most at risk:
- The backflow preventer, the brass assembly that sticks up out of the ground, usually near the house or water meter
- Exposed pipes leading to and from the backflow preventer
- Valves and fittings in shallow valve boxes
When the water inside these parts freezes, it expands. Brass can split, PVC can crack and seals can fail, and you often won’t know until you turn the system back on.
When to winterize your sprinkler system
In Northeast Texas, the first freeze usually arrives sometime in November, but early cold snaps are common. The best approach is to winterize before the first freeze in the forecast, and to keep an eye on the weather all winter.
Pay special attention to a hard freeze: temperatures at or below about 28°F for several hours. A light frost is rarely a problem for an irrigation system. A hard freeze, especially with wind, is when pipes and backflow preventers break.
Know your backflow preventer
Most residential systems in Texas use one of two types:
- Pressure vacuum breaker (PVB): the most common type on homes. It has two ball valves with handles, plus small test cocks on the side.
- Reduced pressure zone assembly (RPZ): a longer assembly with a relief valve on the bottom. These are common on commercial properties and some homes.
Both are winterized the same basic way: shut off the water, drain the assembly and insulate it. If you are not sure which one you have, or how your system is set up, we are happy to take a look.
Step 1: Turn your controller off before a freeze
When temperatures are forecast to drop below freezing, switch your controller to Off or Rain mode. Running sprinklers during a freeze can coat sidewalks, driveways and streets with ice, which is a safety hazard and a liability. It also fills the pipes with water right when you want them empty.
If you have a smart controller, make sure its freeze or temperature shutoff setting is turned on. It will skip watering automatically when it gets too cold.
Step 2: Shut off the water to the sprinkler system
Find the shutoff valve for your irrigation system. It is usually in a small box in the ground near the backflow preventer, or near your water meter. Turn it to the off position before a hard freeze.
This stops water from flowing into the above-ground pipes and backflow preventer, where it would freeze. Your house water stays on; only the sprinkler system is shut off.
Step 3: Drain the backflow preventer
With the water shut off, release the water trapped inside the backflow preventer:
- Use a flathead screwdriver to open the small test cocks on the side of the assembly about a quarter turn. A little water will come out.
- Turn the ball valve handles to a 45-degree angle, halfway between open and closed. This lets water drain out of the valves and keeps the ball inside from cracking.
- If your system has manual drain valves at its low points, open those as well.
We do not recommend blowing out the lines with an air compressor on your own. Too much pressure can crack pipes, damage sprinkler heads and blow out seals, and it is rarely necessary in our climate.
Step 4: Insulate anything above ground
Cover the backflow preventer and any exposed pipes before the freeze:
- Foam pipe insulation on exposed pipe, taped at the seams
- An insulated cover or bag made for backflow preventers, sold at most home improvement and irrigation supply stores
- In a pinch: wrap it in old towels or a blanket, then cover that with a plastic bag to keep it dry. Wet insulation does not protect anything.
On an RPZ assembly, do not seal the relief valve opening on the bottom airtight. Leave room for it to drain.
Leave the cover in place through the coldest part of winter, or at least put it on before every freeze warning.
Step 5: Turn it back on the right way
Once the freeze has passed and temperatures are safely above freezing:
- Close the test cocks.
- Slowly turn the ball valve handles back to fully open. Opening them too fast can send a surge of pressure through the system.
- Turn the water supply back on.
- Run each zone for a few minutes and walk the yard while it runs.
Signs of freeze damage
As each zone runs, watch for:
- Water bubbling up from the ground or soggy spots that weren’t there before
- Sprinkler heads that spray sideways, gush, or don’t pop up at all
- Noticeably low water pressure in a zone
- A zone that won’t shut off
- Water spraying or hissing from the backflow preventer
- A water bill that is higher than normal
If you see any of these, turn the system back off and have it checked. A small leak left running can waste thousands of gallons and wash out soil around your foundation and beds.
Does a dormant lawn still need water in winter?
Occasionally. Bermuda, St. Augustine and zoysia go dormant in winter, but a long dry spell can still stress the roots, especially with cold, dry wind. If you go three to four weeks without meaningful rain, water lightly on a mild day when no freeze is coming, then turn the system back off. One deep watering is better than several light ones.
Common winterizing mistakes
- Leaving the controller running through a freeze
- Covering the backflow preventer without shutting off and draining the water first
- Using insulation that gets soaked and freezes
- Forgetting to uncover and turn the system back on correctly in spring
- Ignoring a small leak after a freeze until the next water bill arrives
Quick winterizing checklist
- ☐ Controller set to Off or Rain mode before a freeze
- ☐ Water to the sprinkler system shut off
- ☐ Test cocks opened and ball valves set halfway
- ☐ Backflow preventer and exposed pipes insulated and kept dry
- ☐ System turned back on slowly and every zone checked after the freeze
Want us to handle it?
Bassett Bro Landscaping provides sprinkler and irrigation services for homes and businesses across Northeast Texas, including seasonal system checks, freeze damage repair, leak detection and line repair, sprinkler head replacement, smart controller installation and backflow testing coordination. Contact us for a free estimate or call (903) 307-9169.
