Backflow preventer cracked after a freeze? What to look for, and what replacement costs
Backflow preventer repair or installation starts at $800 on our price list. Here is how to spot freeze damage and what to do about it.
Short answer: backflow preventer repair and installation start at $800 on our price list. The unit is the brass assembly where your irrigation line connects to the house water supply, and it is the most exposed part of the system in a freeze. A crack usually shows up as water spraying or dripping from the unit as soon as the system is turned on. One note on scope: we repair and install backflow preventers, but we do not do the testing or certification.
What a backflow preventer does
It keeps sprinkler water from flowing backward into your drinking water. Most homes in Atlanta and the north metro have one, either above ground near the house or in a box in the yard. Because it holds water and sits in the open, it is the first place a hard freeze does damage.
Water expands when it freezes. Brass is strong, but it will split along a seam or crack at a fitting if the unit is full when the temperature drops below 32°F. The National Weather Service puts Atlanta's average first freeze at November 13, with an earliest on record of October 11, so the risk starts earlier than most people expect.
Signs of freeze damage
- Water spraying or leaking from the body when the system turns on in spring.
- A steady drip from the relief port that was not there last year.
- Visible hairline cracks or a bulge in the brass.
- A zone that will not run with water pouring out near the unit.
- A jump in the water bill with no change in how you use the system.
If you see any of these, shut the system off at the isolation valve. Do not keep running it to "see if it seals." Water pouring from a cracked unit wastes a lot, and a wet crawl space or a washed-out bed is a bigger repair than the part.
What it costs
| Job | Price | Notes |
|---|---|---|
| Backflow repair or install | from $800 | price list |
| Minimum service call | $95 | price list |
| Winterization (prevents the damage) | $95 – $120 | price list |
A small repair costs less than replacement, but a cracked body usually means replacing the unit. The final number depends on the type of unit, its size and how the plumbing connects to it. We quote the job after we see it, so the number is for your unit and not a guess.
Repair, replace or protect?
- A cracked body or split seam: replace the unit. Patching brass is not a good idea on something tied to your drinking water.
- A worn internal part, with the body sound: repair is possible. That is the case where the lower end of the price makes sense.
- A unit that has never frozen: protect it. A drain-down in the fall and a cover are cheap compared with the alternative.
Example: a winterization at the top of our range is $120. A replacement starting at $800 is nearly seven of those visits, which is why shutting the system down before November is the best money you can spend on it.
DIY, or not?
Turning off the water and draining a unit yourself is reasonable if you know your system. Swapping the unit is a plumbing job tied to your water supply, and the connection has to be right. Your water provider may also have its own rules about testing, so ask them. Testing is done by a certified tester, and that is not a service we offer.
When to call us
Call if you see water at the unit, if a zone will not run after a freeze, or if you are not sure whether your unit was drained. We are licensed and insured, our own crew does the work, and we stop and tell you before doing anything we could not see. We find the cause rather than replacing parts until it stops, so we will check why the unit froze, not only the unit. See the irrigation page or request a quote.
FAQ
How much does it cost to replace a backflow preventer in Atlanta? Repair and installation start at $800 on our price list. The final price depends on the unit type and size and how it connects.
How do I know if my backflow preventer froze? Look for water spraying or dripping from the body, cracks in the brass, or a zone that will not run with water leaking near the unit.
Can a backflow preventer be repaired instead of replaced? If the body is sound and a worn internal part is the problem, yes. A cracked body should be replaced.
Do you test and certify backflow preventers? No. We repair and install them. Testing and certification are done by a separate certified tester.
Prices from Atlanta Irrigation Company's price list. Freeze dates from the National Weather Service, Peachtree City office. Updated October 2026.