1 1/2" Backflow Preventer Cost
Mostly commercial irrigation and building lines. Live parts prices from our Rocklin, CA warehouse, plus what a certified tester typically charges.
Short answer
Most 1 1/2-inch backflow preventer repairs are a rubber rebuild kit, which costs $42 – $246 in parts. A certified tester typically charges $150 – $350 in labor to install it and retest the device — so a standard 1 1/2-inch rebuild lands around $192 – $596 all in.
Replacing the entire assembly instead costs $471 – $2,225 for the device, plus $350 – $800 labor. Repair is cheaper in nearly every case where the body is still sound.
Parts prices are live from our own inventory of 78 1 1/2-inch repair parts and 13 complete 1 1/2" assemblies. Updated October 15, 2026.
1 1/2" Backflow Repair Cost at a Glance
On a 1 1/2" device the parts and the labor are both bigger numbers than on a home-size device, and a new assembly is a real expense. Here is how they compare.
| Job | Parts (our pricing) | Typical labor | Total |
|---|---|---|---|
| Annual certification test | — | $45 – $125 | $45 – $125 |
| Rubber rebuild (most common) | $42 – $246 | $150 – $350 | $192 – $596 |
| Single component (spring, retainer, poppet) | $10 – $149 | $150 – $350 | $160 – $499 |
| Major sub-assembly (check, relief valve, vessel) | $65 – $680 | $150 – $350 | $215 – $1,030 |
| Full assembly replacement | $471 – $2,225 | $350 – $800 | $821 – $3,025 |
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 1 1/2" Backflow Repair Parts Cost?
These are live prices from our Rocklin warehouse. We stock 1 1/2" rebuild kits, check modules, and relief valve parts for double checks, RPZs, and vacuum breakers from the major brands.
How much is a rebuild kit for a 1 1/2 inch backflow preventer?
A rubber rebuild kit is what fixes the large majority of failed annual tests. For 1 1/2-inch devices these run $42 – $246, with most single-check kits landing near $90.
| Part | Brand | Price |
|---|---|---|
| Wilkins 1 1/4", 1 1/2", and 2" 950XLT/950XLT2 Seat Kit | Wilkins | $41.98 |
| Wilkins 1 1/4", 1 1/2", and 2" 350/350XL 1st and 2nd Check Rubber Rebuild | Wilkins | $41.98 |
| Watts 1 1/4"-1 1/2" 009M2 2nd Check Rubber Rebuild | Watts | $43.98 |
| Watts 1 1/4"-1 1/2" 009M2 1st Check Rubber Rebuild | Watts | $43.98 |
| Seat Kit | Wilkins | $43.98 |
| 1st and 2nd Check Rubber Rebuild | Wilkins | $47.98 |
| Watts 1 1/4", 1 1/2", and 2" 009M1 2nd Check Rubber Rebuild | Watts | $49.98 |
| Watts 1 1/4", 1 1/2", and 2" 009M1 1st Check Rubber Rebuild | Watts | $49.98 |
Should You Repair or Replace a 1 1/2" Backflow Preventer?
At this size a new assembly costs many times what a rebuild does, so rebuild unless 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 is cracked from freeze damage
- Brass is corroded or pitted through
- The model is obsolete and parts are gone
- It has failed repeatedly after rebuilds
- Code requires a higher hazard rating (DC → RPZ)
Freeze damage is the expensive one
Replacing a frozen 1 1/2" assembly is an expensive surprise in winter. An insulated freeze bag costs a small fraction of that. We stock Sub Zero Covers bags, made in the USA, in Rocklin. See our freeze bags.
What Fails on a 1 1/2 Inch Backflow Preventer — and What It Costs
| Symptom | Likely cause | Part you need |
|---|---|---|
| Relief valve drips continuously | Fouled or worn first check | 1st check rubber rebuild kit |
| Failed test — check valve leaking back | Hardened check discs | Complete rubber repair kit |
| Relief valve won't open at spec | Worn relief valve seat or O-ring | Relief valve rubber rebuild |
| Spitting from air inlet (PVB) | Worn poppet or float | Check poppet / seat kit |
| Test cock won't seal | Damaged test cock | Replacement test cock |
| Cracked body after a freeze | Freeze damage | Complete replacement assembly |
How to Order the Right 1 1/2" Part
Many brands build their 1 1/4" to 2" devices on related bodies, so kits can look interchangeable when they aren't. Go by the tag.
- Find the tag on the body or bonnet and note the brand, size, and model, for example Watts 1 1/2" 909 or Febco 1 1/2" 860.
- Note what failed: the first check, the second check, or the relief valve. 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 in-stock 1 1/2" parts ship the same or next business day from Rocklin. If a part is special order, we'll tell you the lead time up front.
1 1/2 Inch Backflow Preventer Cost — Frequently Asked Questions
How much does it cost to fix a 1 1/2 inch backflow preventer?+
Most 1 1/2" repairs are a rubber rebuild kit, which costs $42 – $246 in parts depending on the brand and whether you rebuild one check or the whole device. A certified tester typically charges $150 – $350 to install it and retest, so a standard 1 1/2" rebuild comes to about $192 – $596.
Is it worth rebuilding a 1 1/2 inch backflow preventer?+
Almost always. A 1 1/2" kit costs $42 to $246, while a complete 1 1/2" assembly runs $471 – $2,225 before labor. Rebuilding only stops making sense when the body is cracked or corroded, the model is obsolete, or it keeps failing after rebuilds.
How much is a new 1 1/2 inch backflow assembly?+
Complete 1 1/2" assemblies run $471 – $2,225, depending on the brand and type. Double checks are at the lower end and RPZs at the higher end, and we quote the exact price for your model. Typical labor to swap it and certify it runs $350 – $800.
Is a 1 1/2 inch rebuild kit the same as a 2 inch kit?+
Sometimes. Some models share one kit across 1 1/4" to 2", and others use a different kit for every size. The repair parts finder lists the kits that fit your exact model and size, or send us the tag and we'll match it.
Where are 1 1/2 inch backflow preventers used?+
Mostly commercial: irrigation for parks, schools, and HOAs, and the domestic water service of small and mid-size buildings. That is why many of them are RPZs, which most water providers require on higher-hazard connections.
How much does a 1 1/2 inch backflow test cost?+
An annual certification test typically runs $45 – $125. Commercial sites with several devices often get a better rate per device. If one fails, the tester quotes the repair separately.
Do I need a certified tester to repair a 1 1/2 inch backflow?+
In California and most other places, yes. A certified backflow tester has to test the device after any repair and file the report with your water provider. You can buy the parts yourself, but the repair and test need to be documented by a certified tester.
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 1 1/2-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 1 1/2" 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.