Backflow Testing and Prevention Assembly Service in Denver and Aurora

Backflow Testing in Denver

Deft Plumbing is certified to test backflow prevention assemblies across the Denver metro — RPZ, double-check, and pressure vacuum breaker units on irrigation systems, boilers, and commercial connections. Most Front Range water providers require these assemblies to be tested every year by a certified tester, and we handle the test, the paperwork, and the result filed with your provider. Flat-rate quote before we start, no hourly surprises. Call (720) 880-8064.

A backflow preventer is the device standing between your sprinkler system or boiler loop and the drinking water in your house — and your neighbors'. When a check valve or relief valve inside it wears out, it can let contaminated water siphon back into the potable supply. The annual test confirms the assembly still holds. We diagnose first: if the unit fails, we tell you whether it needs a repair kit or a full replacement before any work starts.

What Backflow Testing Is and Why Your Water Provider Requires It

Backflow happens when the pressure in a water line drops — a main break, a heavy draw, or a pump kicking on — and pulls water backward through a cross-connection. A cross-connection is any point where the potable supply meets a potential contaminant: irrigation water sitting in a sprinkler line, chemically treated water in a boiler loop, or a commercial process. A backflow prevention assembly stops that reversal and keeps the contaminant out of the drinking water.

Denver-area water providers run cross-connection control programs, and they require the assemblies on irrigation systems, fire lines, boilers, and commercial accounts to be tested every year by a certified tester, with the results submitted to the provider. Miss the test and the provider can issue a notice and, in some cases, shut off service to the connection until it is tested.

We identify the assembly type, run the test with a calibrated gauge, and file the report so your account stays compliant. You get a copy for your records.

The Assemblies We Test — RPZ, Double-Check, and PVB

There are three assembly types common on Denver metro properties, and the right one depends on the hazard level of the connection.

Reduced pressure zone assembly (RPZ) — the highest level of protection, required where the hazard is high, such as boilers with chemical treatment and commercial equipment. It uses two check valves and a relief valve that dumps water to open air if either check fails, so a failure is visible rather than silent.

Double-check valve assembly (DCVA) — two independent check valves in series, used for lower-hazard connections like most lawn irrigation.

Pressure vacuum breaker (PVB) — the common choice on residential sprinkler systems, mounted above grade and above the highest sprinkler head so it can break a vacuum before water siphons back.

We test the check valves and the relief valve with a calibrated differential pressure gauge, confirm each one holds within the required spec, and record the readings on the provider's report.

Front Range Freeze-Thaw and Spring Startup

Above-ground assemblies — pressure vacuum breakers on irrigation especially — take a beating over a Colorado winter. Water left in the body freezes, cracks the bonnet or the internal poppet, and the unit fails at the next test. That is why spring sprinkler startup is the busiest backflow season on the Front Range.

The fix is cheap compared to the failure: blow out the irrigation system before the first hard freeze so no water is left to expand, then test at startup. If we find a cracked body or a failed check at startup, we tell you up front whether a repair kit restores it or the assembly needs replacing, with a flat-rate quote either way. We handle the same freeze-prone exterior work on outside spigot replacements.

What a Deft Backflow Test Looks Like

We start by locating and identifying the assembly — type, size, make, model, and serial number — because the provider's report needs all of it. We close the downstream shutoff, attach the calibrated test gauge to the test cocks, and read each check valve and the relief valve against the required minimums.

A single residential assembly takes about 20 to 30 minutes. We complete the water provider's test report with the readings and submit it. If the assembly passes, you are done for the year. If it fails, we show you the readings and quote the repair or replacement before we touch it — diagnose first, flat-rate price, no pressure.

Repairs and Replacement When an Assembly Fails

A failed assembly is usually a worn check spring, a fouled poppet, or a cracked relief valve seat — often fixable with a manufacturer repair kit for Febco, Watts, Zurn Wilkins, and similar brands. When the body is cracked from a freeze or the unit is obsolete with no kit available, replacement is the honest call rather than chasing a part that no longer exists.

We size the replacement to the connection, install it to code and provider spec, and retest to confirm it passes before filing the report. Bundling the repair or replacement with the test in one visit avoids a second service call. A failing assembly often sits alongside aging shutoffs, so if we find seized valves at the connection we can address those under valve replacements in the same trip.

Backflow Testing FAQs

Do I need a backflow test in Denver or Aurora?

If you have a lawn irrigation or sprinkler system, a boiler, a fire sprinkler line, or a commercial connection, your water provider almost certainly requires a backflow prevention assembly and an annual test by a certified tester. Residential irrigation systems are the most common trigger. Call us with your address and we will tell you what your provider requires. Call (720) 880-8064.

How often does a backflow preventer need testing?

Most Front Range water providers require testing once a year, with the report submitted by a set deadline, and new assemblies are tested at installation. We can set a yearly reminder so you do not miss the window and risk a shutoff notice.

How long does a backflow test take?

A single residential assembly takes about 20 to 30 minutes, including locating the unit, attaching the calibrated gauge, reading the check valves and relief valve, and filling out the provider's report. Several assemblies on one property take longer but usually cost less per unit when done in one visit.

What happens if my backflow assembly fails the test?

We show you the gauge readings and tell you whether a repair kit will restore the assembly or it needs replacing. Common failures are a worn check spring, a fouled poppet, or a freeze-cracked body. We give a flat-rate quote for the fix before any work starts, and we retest after the repair to confirm it passes before filing the report.

Why did my sprinkler backflow preventer fail after winter?

Above-ground assemblies like pressure vacuum breakers hold water that freezes and cracks the body or internal parts over a Colorado winter. Blowing out the irrigation system before the first hard freeze prevents most of this. If yours cracked, we quote a repair kit or a replacement at spring startup.

Can you file the test report with my water provider?

Yes. Completing the provider's test report with the assembly details and gauge readings and submitting it is part of the service, so your account stays compliant. You get a copy for your records.

Need Backflow Testing?

Contact Deft Plumbing for a free, upfront quote. No surprises, no hidden fees. We're licensed, bonded, and insured for your protection.

Call (720) 880-8064 or request a free estimate online.

Related Services

Service Areas

We provide backflow testing services across the Denver metro area, including Aurora, Lakewood, Arvada, Westminster, Thornton, Broomfield, and more.

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