3/4" Backflow Preventer Cost
The size on most homes and small irrigation systems. Live parts prices from our Rocklin, CA warehouse, plus what a certified tester typically charges.
Short answer
Most 3/4-inch backflow preventer repairs are a rubber rebuild kit, which costs $19 – $180 in parts. A certified tester typically charges $100 – $250 in labor to install it and retest the device — so a standard 3/4-inch rebuild lands around $119 – $430 all in.
Replacing the entire assembly instead costs $187 – $822 for the device, plus $200 – $500 labor. Repair is cheaper in nearly every case where the body is still sound.
Parts prices are live from our own inventory of 102 3/4-inch repair parts and 15 complete 3/4" assemblies. Updated October 15, 2026.
3/4" Backflow Repair Cost at a Glance
A 3/4" repair is usually a small job. The parts are the part we sell, and the labor is what your tester charges. Looking at the two separately makes it easy to check a quote.
| Job | Parts (our pricing) | Typical labor | Total |
|---|---|---|---|
| Annual certification test | — | $45 – $125 | $45 – $125 |
| Rubber rebuild (most common) | $19 – $180 | $100 – $250 | $119 – $430 |
| Single component (spring, retainer, poppet) | $8 – $111 | $100 – $250 | $108 – $361 |
| Major sub-assembly (check, relief valve, vessel) | $36 – $274 | $100 – $250 | $136 – $524 |
| Full assembly replacement | $187 – $822 | $200 – $500 | $387 – $1,322 |
About the labor figures: The Backflow Depot supplies parts, assemblies, and rentals — we do not perform repairs or testing. Labor columns are typical market rates charged by independent certified backflow testers in Northern California, provided for context only. Your tester's quote is the authoritative number.
Not sure which part your device needs?
Send us your device brand, size, and model number and we'll identify the exact rebuild kit and quote it — usually the same business day.
Send us your device brand, size, and model — we'll come back with exact part pricing and availability.
What Do 3/4" Backflow Repair Parts Cost?
These are live prices from our Rocklin warehouse. We stock 3/4" rebuild kits, poppets, springs, and test cocks for pressure vacuum breakers, double checks, and RPZs from the major brands.
How much is a rebuild kit for a 3/4 inch backflow preventer?
A rubber rebuild kit is what fixes the large majority of failed annual tests. For 3/4-inch devices these run $19 – $180, with most single-check kits landing near $53.
| Part | Brand | Price |
|---|---|---|
| Febco 1/2"-3/4" 850/860 1st and 2nd Check Rubber Rebuild | Febco | $18.98 |
| Watts 3/4" 919 1st or 2nd Check Rubber Rebuild | Watts | $22.98 |
| Watts 3/4"-1" 009 First Check Rubber Rebuild | Watts | $22.99 |
| Watts 3/4"-1" 709 Complete Rubber Rebuild | Watts | $27.98 |
| Wilkins 3/4"-1" 975/975XL/975XL2 Relief Valve Rubber Rebuild | Wilkins | $27.98 |
| Wilkins 3/4" 350/350XL Complete Rubber Rebuild | Wilkins | $28.98 |
| Wilkins 1/2" - 3/4" 420/420XL Complete Rubber Rebuild | Wilkins | $32.98 |
| Wilkins 3/4" - 1" 950 Check Seat Kit | Wilkins | $33.65 |
Should You Repair or Replace a 3/4" Backflow Preventer?
On a 3/4" device the gap between a rebuild and a new assembly is smaller than on bigger sizes, so replacing is a fair call more often. Rebuild when the body is sound, and replace when one of these is true.
Rebuild it when…
- It failed the annual test but holds pressure
- Rubber is worn, hardened, or fouled with debris
- The relief valve weeps or drips continuously
- The body and springs are undamaged
- Parts are still manufactured for the model
Replace it when…
- The body or bonnet split in a freeze
- The brass is corroded or the threads are stripped
- The model is obsolete and kits are hard to find
- It keeps failing its test after rebuilds
- Your water provider now requires an RPZ instead
Freeze damage is the expensive one
Most 3/4" devices sit above ground in a yard, which makes them the ones most likely to split in a cold snap. An insulated freeze bag costs far less than a new device. We stock Sub Zero Covers bags, made in the USA, in Rocklin. See our freeze bags.
What Fails on a 3/4 Inch Backflow Preventer — and What It Costs
| Symptom | Likely cause | Part you need |
|---|---|---|
| Water spits from the top of a PVB | Worn poppet or air inlet seat | Poppet / bonnet rebuild kit |
| Relief valve drips continuously | Fouled or worn first check | 1st check rubber kit |
| Failed test, check leaking back | Hardened check rubber | Complete rubber repair kit |
| Test cock won't seal | Damaged test cock | Replacement test cock |
| Leaks at the bonnet or cover | Worn cover O-ring | O-ring / gasket kit |
| Cracked body after a freeze | Freeze damage | Complete replacement assembly |
How to Order the Right 3/4" Part
Kits for 3/4" and 1" devices often look alike but don't fit each other. The tag on the device has everything you need.
- Find the tag on the body or bonnet and note the brand, size, and model, for example Febco 3/4" 765 or Watts 3/4" 009.
- Note what failed: the first check, the second check, the relief valve, or the air inlet on a vacuum breaker. Your tester's report says which.
- Match the part in the repair parts finder by brand, size, and model, or send us the tag details and we'll confirm it.
Most 3/4" kits are on the shelf in Rocklin and ship the same or next business day. If something is special order, we'll tell you the lead time up front.
3/4 Inch Backflow Preventer Cost — Frequently Asked Questions
How much does it cost to fix a 3/4 inch backflow preventer?+
Most 3/4" repairs are a rubber rebuild kit, which costs $19 – $180 in parts depending on the brand and the type of device. A certified tester typically charges $100 – $250 to install it and retest, so a standard 3/4" rebuild comes to about $119 – $430 all in.
Should I repair or replace a 3/4 inch backflow preventer?+
Repair it if the body is sound. A typical 3/4" kit costs about $53, while a complete 3/4" assembly runs $187 – $822 before labor. Because the gap is smaller than on bigger devices, replacing is reasonable when the body split in a freeze, the model is obsolete, or it keeps failing after rebuilds.
Why is water spraying from the top of my 3/4 inch backflow?+
On a pressure vacuum breaker, a short spurt when the water first comes on is normal. Steady spraying or dripping from the top usually means the poppet or the air inlet seat is worn or has debris on it, and a poppet or bonnet kit fixes it. If the bonnet itself is cracked, that is freeze damage.
Can I rebuild a 3/4 inch backflow preventer myself?+
You can buy the parts yourself. In California the device has to be tested by a certified backflow tester after a repair, and the test report goes to your water provider, so most homeowners have the tester do the rebuild while they are there.
How much does a 3/4 inch backflow test cost?+
An annual test on a 3/4" device typically runs $45 – $125, depending on your area and whether the tester has other stops nearby. If it fails, the tester quotes the repair separately.
What usually goes wrong on a 3/4 inch backflow preventer?+
Two things. The rubber parts harden and wear over the years, which causes most failed tests and is a cheap fix. And because these devices usually sit outside above ground, a hard freeze can split the body or bonnet, which usually means replacing the device.
How do I keep a 3/4 inch backflow from freezing?+
Drain it before a freeze if it is on an irrigation line you can shut off, and cover it with an insulated freeze bag sized to the device. A bag that fits snugly holds heat much better than a loose blanket or a bucket. Our freeze bag sizing guide shows which size fits your device.
Guides for getting the part right
- Wilkins 975XL vs 975XL2 vs 975XL3: Which Kit You Need975XL and 975XL2 share the same repair kits for a given size. 975XL3 is a different design with its own kits. Read the tag, then use this size and model map with links to each kit.
- Watts 009M2 Repair Kit: What’s in a Complete Rubber RebuildThe Watts 009M2 / LF009M2 complete rubber rebuild (RT kit) covers both checks and the relief valve. Here is what is in it, how RT differs from RV and VT kits, and the shop link for each size.
- How to Read a Backflow Preventer Tag (Brand, Size, Model) Before You OrderBrand, size and model are on the metal ID plate or stamped on the shutoffs. Read all three before you order a repair kit or freeze bag, and photograph the tag if you want counter help.
- Freeze Bag vs Heated Enclosure for Backflow: When Each Wins in NorCalIn Northern California a fitted freeze bag is the usual answer for residential and light-commercial assemblies. A heated enclosure wins when the line cannot freeze or the spec names ASSE 1060 Class I.
- How to Measure a Backflow Preventer for a Freeze BagSize a freeze bag off the full installed assembly: length, width, height and pipe size. We match it to one of five standard sizes, going up one if you are between. Use the photo sizer for 3-inch and larger.
Where these prices come from
The Backflow Depot supplies backflow prevention parts, assemblies, and freeze bags from our warehouse in Rocklin, California. The 3/4-inch parts prices on this page come straight from our live inventory of 1,000+ backflow repair parts and assemblies, not from industry averages. We are an authorized dealer for Watts, Febco, Wilkins, Apollo/Conbraco, Ames, Deringer, ARI, and Rain Bird, and we serve contractors, certified testers, municipalities, and property owners across 16 Northern California counties.
CCL# 934557 · AWWA Member #12508 & #14926 · Sacramento County EMD #554 & #1104 · Prices last updated October 15, 2026
Authorized Dealer for Leading Brands
Get exact pricing for your 3/4" device
Tell us the brand, size, and model on the tag. We'll confirm the right kit or replacement, the price, and whether it's in stock.
Send us your device brand, size, and model — we'll come back with exact part pricing and availability.