The backflow sitting by the hose bib is the freeze magnet of Texas irrigation. Dallas and Boerne learn this every norther; Austin learns it on the odd ice week. A dripping relief on a RPZ is a warning. Capping it is how people contaminate a service line and fail inspection.
This guide is written for Texas systems — Blackland prairie clay that heaves after freezes in Dallas, freeze risk in Austin, watering rules from Dallas Water Utilities. It is not a national blog with the city name swapped in. If the hardware is already failing, skip to emergency repairs or call 888-427-5022.
What a leaking backflow preventer actually looks like on a Texas lawn
Water from the relief valve. A cracked brass body after a freeze. A backflow that sprays when the system starts. An insulation bag that was never put back after spring.
In Dallas the same symptom often traces to freeze-cracked backflows and heaved heads. In Austin we see more freeze and heave. In Boerne (City of Boerne) the program may be legal but the heads are wrong. Do not assume the YouTube fix matches Dallas Water Utilities pressure.
Diagnose before you buy parts
Order of operations matters. Controller and rain sensor first, then the valve box, then heads with water on, then a shovel. Skipping steps is how people replace nozzles when the solenoid is open, or trench for a “root problem” when station 4 is dead at the clock.
- If it is gushing, shut the irrigation isolation and the valves on the backflow.
- Do not cap a relief port. That is not a repair.
- After a freeze, look for cracks before you run the first cycle. A cracked body under pressure undermines the slab edge.
- Insulation and covers are cheaper than brass. Put them on before the forecast, not during it.
- Repairs and tests belong with people who know RPZ vs double-check. Cities care.
Keep a notepad of zone numbers. The FAQ covers the phone questions we ask so the truck shows up with the right fittings.
Parts that actually last in this climate
Covers, insulation, rebuild kits for the model you have, and in worst cases a replacement assembly. Cheap covers blow off in Fort Worth wind — strap them.
We use matched-precipitation nozzles when we change a head, and we flush grit after a pipe cut so the next screen does not pack. Brand-specific notes live in the blog as well — start with Clogged Drip Irrigation in Texas, Cycle and Soak for Texas Clay, How to Winterize a Sprinkler System in Texas.
What it costs in Texas (ranges, not bait)
A rebuild can be reasonable. A freeze-cracked body is a replacement. Testing may be required by your city after work. We do not treat that as optional paperwork.
A written quote before work is the rule. See Emergency Repairs for what a typical visit includes, and the full service list if more than one system is involved.
DIY vs calling a licensed irrigator
Covers and shutoff before a freeze are DIY. Rebuilding an RPZ is not a Saturday YouTube if your city tests. Capping a relief is never DIY, it is a hazard.
Texas licenses landscape irrigators for a reason: backflow, buried electric, and municipal rules. If you are in Dallas, Austin, or Boerne, start on the city page — Dallas, Austin, Boerne — then book.
Mistakes that turn a one-hour job into a weekend
- Capping the relief because it dripped.
- Leaving the backflow uninsulated in DFW from November to March.
- Running the system to “see if it still works” after an ice storm without looking at the brass.
How this ties to other repairs
Freeze prep and emergency shutoff live next to this article. A leaking backflow can also look like a high bill. Meter-test first if it is a drip, not a spray.
Coverage problems after a “fix” usually mean the program was never updated. Pair mechanical work with controller programming and, on clay, cycle-and-soak — not a longer single runtime.
What a good visit looks like on our trucks
We do not start with a parts cannon. Controller and sensor, then the box, then water-on, then dirt if the lateral is the problem. That order is how you avoid replacing a clock for a cut wire, or trenching a puddle that is eight feet from the break. If you want the short phone version, the FAQ is enough. If you want the long version, you are already in it.
Texas jobs change by metro even when the part number does not. Dallas clay hides water. Austin actually freezes brass. Boerne bills you through a different utility window. A national blog that only swaps the city name is how Google ends up indexing one page. We write the local constraint in the article because it changes the repair.
Bring zone numbers, whether the problem is new or slow, whether anyone dug recently, and whether the meter moves when everything should be off. Those four answers route the call — leak truck vs simple head work vs controller power path. Book on contact or call 888-427-5022.
Frequently asked
Why is it dripping a little?
Relief valves weep with pressure spikes or a failing seat. Small drip still wants a rebuild, not a cap.
Houston barely freezes. Do I care?
Uri said otherwise. Exposed brass still hates 20°F, even if it only happens some years.
Need it fixed, not diagnosed over email? Call 888-427-5022 or use the contact page. Same-day windows are for active leaks and stuck-on valves. Everything else we schedule on emergency vs standard priority.
Texas context we will not skip
Gulf clay, Blackland prairie, and Edwards rock do not share a repair script. A wet spot in Houston is not a freeze crack in Dallas, and a SAWS stage day is not a MUD watering window in Katy. We write those constraints because they change the parts on the truck and the program we leave on the clock.
If this article is about a part, still run isolation before you buy a case of that part. If it is about a city, still open the valve box before you trench the first damp patch. If it is about a clock, still measure the solenoid. That order is the whole business.
Call 888-427-5022. Use the contact page if you need a gate code on the ticket. Hub pages: services, service areas, blog.