BackflowNear Test-Due Reminder

Approved backflow testers in Thornton, CO

39 backflow testing businesses work within 25 miles of Thornton, 2 of them based in town. Every one is on the approved tester list of 6 water utilities.

39 businesses within 25 miles

Backflow testing companies near Thornton

Most of these businesses are also listed on Westminster, CO.

What the badges mean
✓ CO Utility-Approved Tester Verified On the city list
The company is on a water utility's own approved list (the second badge names the list). That is the utility's approval, not a state license, and it counts for that utility.
3 certified testers
How many certified testers the roster lists at this business.
★ 4.8 (25 reviews)
The Google rating, shown as Google reports it. It does not change the order.

Order is by our quality score, never by payment. How we verify listings.

Are you a backflow testing company near Thornton? One sponsor per county, clearly labelled. Sponsor this county

Murphy Company

90/100
✓ CO Utility-Approved Tester Verified ★ 3.8 (52 reviews) On City of Longmont list Backflow Testing

12789 Emerson St, Thornton, CO 80241 · under 1 mile from Thornton

Call (303) 371-6600 Details Website
Verified Oct 2026 · Unclaimed listing

Mtech Mechanical

90/100
✓ CO Utility-Approved Tester Verified ★ 4.3 (81 reviews) On City of Longmont listOn Town of Berthoud list Backflow Testing

12300 N Pecos St, Westminster, CO 80234 · 1 mi from Thornton

Call (303) 650-4000 Details Website
Verified Oct 2026 · Unclaimed listing

Cintas Fire Protection

90/100
✓ CO Utility-Approved Tester Verified ★ 4.6 (171 reviews) On Eagle River Water & Sanitation listOn City of Longmont listOn Town of Berthoud list Backflow Testing

1100 W 120th Ave #500, Westminster, CO 80234 · 2 mi from Thornton

Call (303) 993-1622 Details Website
Verified Oct 2026 · Unclaimed listing

Procraft Mechanical

90/100
✓ CO Utility-Approved Tester Verified ★ 3.5 (25 reviews) On City of Longmont list Backflow Testing

2400 Industrial Ln #500, Broomfield, CO 80020 · 6 mi from Thornton

Call (303) 952-8668 Details Website
Verified Oct 2026 · Unclaimed listing

Design Mechanical Inc

90/100
✓ CO Utility-Approved Tester Verified ★ 4.1 (24 reviews) On Eagle River Water & Sanitation list Backflow Testing

312 Ctc Blvd, Louisville, CO 80027 · 8 mi from Thornton

Call (303) 449-2092 Details Website
Verified Oct 2026 · Unclaimed listing

Vectra Mechanical

90/100
✓ CO Utility-Approved Tester Verified ★ 4.9 (375 reviews) On City of Longmont list Backflow Testing

5610 N Lamar St, Arvada, CO 80002 · 10 mi from Thornton

Call (720) 353-1079 Details Website
Verified Oct 2026 · Unclaimed listing

Martin Fire Protecton Inc

80/100
✓ CO Utility-Approved Tester Verified ★ 3 (4 reviews) On City of Longmont list Backflow Testing

12295 Pennsylvania St #4b, Thornton, CO 80241 · under 1 mile from Thornton

Call (303) 425-6678 Details
Verified Oct 2026 · Unclaimed listing

Advanced Backflow LLC

80/100
✓ CO Utility-Approved Tester Verified On Town of Berthoud list Backflow Testing

4550 W 90th Ave, Westminster, CO 80031 · 6 mi from Thornton

Call (303) 427-5556 Details
Verified Oct 2026 · Unclaimed listing

Braconier

90/100
✓ CO Utility-Approved Tester Verified ★ 3.4 (38 reviews) On Colorado Springs Utilities list Backflow Testing

4925 Nome St, Denver, CO 80239 · 12 mi from Thornton

Call (303) 777-3037 Details Website
Verified Oct 2026 · Unclaimed listing

Frontier Fire

90/100
✓ CO Utility-Approved Tester Verified ★ 4 (62 reviews) On Eagle River Water & Sanitation listOn City of Longmont listOn City of Aspen list Backflow Testing

9430 E 40th Ave, Denver, CO 80238 · 12 mi from Thornton

Call (303) 629-0221 Details Website
Verified Oct 2026 · Unclaimed listing

Redline Fire Solutions

90/100
✓ CO Utility-Approved Tester Verified ★ 4.3 (6 reviews) On Colorado Springs Utilities listOn City of Longmont list Backflow Testing

2695 W 3rd Ave, Denver, CO 80219 · 14 mi from Thornton

Call (303) 423-2252 Details Website
Verified Oct 2026 · Unclaimed listing

Foster Plumbing

90/100
✓ CO Utility-Approved Tester Verified ★ 4.3 (49 reviews) On City of Longmont list Backflow Testing

1531 W Bayaud Ave A, Denver, CO 80223 · 15 mi from Thornton

Call (303) 752-5332 Details Website
Verified Oct 2026 · Unclaimed listing

Backflow Tech

90/100
✓ CO Utility-Approved Tester Verified ★ 4.3 (19 reviews) On Cherokee Metro District listOn City of Longmont listOn Town of Berthoud listOn City of Aspen list Backflow Testing

610 Garrison St, Lakewood, CO 80215 · 15 mi from Thornton

Call (303) 986-4601 Details Website
Verified Oct 2026 · Unclaimed listing

Backflow Consulting Testing & Repair

90/100
✓ CO Utility-Approved Tester Verified ★ 4.7 (22 reviews) On Eagle River Water & Sanitation listOn Colorado Springs Utilities listOn City of Longmont list Backflow Testing

15430 E Batavia Dr b, Aurora, CO 80011 · 15 mi from Thornton

Call (303) 537-0126 Details Website
Verified Oct 2026 · Unclaimed listing

Streamline Plumbing, LLC

90/100
✓ CO Utility-Approved Tester Verified ★ 4.9 (161 reviews) On City of Longmont listOn Town of Berthoud list Backflow Testing

1740 Skyway Dr, Longmont, CO 80504 · 16 mi from Thornton

Call (303) 772-2250 Details Website
Verified Oct 2026 · Unclaimed listing

Solid Grounds Inc.

90/100
✓ CO Utility-Approved Tester Verified ★ 4.7 (38 reviews) On City of Longmont list Backflow Testing

1885 Vista View Dr Unit a, Longmont, CO 80504 · 16 mi from Thornton

Call (303) 651-1087 Details Website
Verified Oct 2026 · Unclaimed listing

Vulcan Fire & Security

90/100
✓ CO Utility-Approved Tester Verified ★ 4.1 (27 reviews) On Eagle River Water & Sanitation listOn Town of Berthoud list Backflow Testing

14828 W 6th Ave Unit 12-B, Golden, CO 80401 · 17 mi from Thornton

Call (303) 973-7412 Details Website
Verified Oct 2026 · Unclaimed listing

Cosco Fire Protection

90/100
✓ CO Utility-Approved Tester Verified On City of Longmont listOn Town of Berthoud list Backflow Testing

6611 N Powhaton Rd Unit 110, Aurora, CO 80019 · 17 mi from Thornton

Call (720) 599-8800 Details Website
Verified Oct 2026 · Unclaimed listing

Price reports

What a backflow test costs in Thornton

Not enough reports yet for Thornton to show a range. Be one of the first: it takes a minute and stays anonymous.

Published prices nationwide

$29.99 to $100 per assembly

Based on 14 published prices · Read Oct 2026 Prices testing businesses list on their own websites, from our cost guide. Listed prices, not what people paid.

Every published price, with its source: what a backflow test costs.

Failed test? Published repair, rebuild and replacement prices: what a backflow repair or replacement costs.

Had your backflow test done? Share what you paid to see local prices.

Metro guide: Backflow testing in Denver: every utility's rules, filing portals and published prices in one place.

Never miss your annual backflow test

Most water utilities require the backflow assembly on an irrigation, fire or commercial line to be tested every year, and a missed test can mean a shutoff notice. Tell us when yours was last tested in Thornton and we'll text you a month before it is due, with certified local testers ready to book.

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Backflow testing questions in Thornton

Where are the backflow testing businesses listed for Thornton based?

39 backflow testing businesses are listed within 25 miles of Thornton. 2 are based in Thornton itself, 20 more within 15 miles and 17 further out, up to 25 miles away. Other towns with more than one listing: Denver (8), Longmont (7) and Lakewood (4). The closest is Murphy Company, under 1 mile from Thornton.

Which tester lists are the businesses near Thornton on?

Every one is on the approved tester list of 6 water utilities.

How many of the backflow testing businesses near Thornton have Google reviews?

34 of the 39 listed for Thornton have 3 or more Google reviews. Mountain Alarm Fire & Security has the most reviews, 416, with an average of 4.7 stars, as Google showed them at our last check.

Approved list: City of Longmont backflow tester contact list, City of Longmont Water.

Approved list: Colorado Springs Utilities registered backflow testers, Colorado Springs Utilities.

Approved list: Eagle River Water & Sanitation District certified backflow test company directory, Eagle River Water & Sanitation District.

Approved list: Town of Berthoud backflow inspection and testing companies (tested in 80513), Town of Berthoud.

Approved list: City of Aspen certified backflow tester list, City of Aspen Utilities.

Approved list: Cherokee Metropolitan District backflow tester list, Cherokee Metropolitan District.

Approved list: City of Grand Junction certified backflow tester list, City of Grand Junction Water Services.

Approved list: Security WSD approved list of certified backflow testers, Security Water and Sanitation Districts.

Approved list: City of Durango licensed and certified cross connection control testers, City of Durango Cross Connection Control Program.

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