Duncan Plumbing

Plumber and Backflow Testing in San Antonio
Opening at 8:00 AM on Monday
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Leaking Backflow? We repair backflow devices, replacement is not always the best option. We offer affordable backflow testing, backflow repairs, and backflow replacements. If you own a restaurant or medical facility, we have affordable testing rates for multiple tests. We are fully licensed a...

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Did You Know?? Most large plumbing companies that are advertised on TV charge over $200.00 per hour for plumbing services, not to mention unreal parts markups of over 300%. Our services are nearly half the cost of the large companies. if you have been given prices for any of the following repa...

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We repair ALL plumbing problems including, water softeners, water heaters(tank and tankless), gas leaks, gas lockouts, drain cleaning, drain repair, water leak locating with FLIR cameras, foundation leak re-routes, yard leaks, backflow testing, backflow repair and loads more. We are the water pr...

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Premature water heater failures can be prevented by flushing calcium and lyme build up from your heater regularly, changing your anode rod every 5 years, and having a thermal expansion tank. This will keep your heater in tip tip shape!

Happy Holidays to all! We appreciate everyones business this year. Our first year is coming to a close and will be spending time with our families untill January 8th. Please call and leave a message and calls will be retured after the 8th. We wish everyone have safe travels, family time, and a...

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Plumbing problems are usually caused by a bad installation. Don't let this happen to you. We use the best materials and knowledge for a lasting solution to your problems. Call us for expert repairs, that won't kill your budget. 210-400-1238

We do yard leaks, fast! Leaks usaully located and exposed in less than 1 hour! Call us to find out more 210-400-1238

We do drain cleaning! Call us to get those old drains flowing. We Guarantee our cleaning services for a minimum of 30 Days.

Recirculation systems are available for all homes!! Whether you have a recirculation line or not. Call us to get faster hot water, save water, time and money.


2 years ago
This plumber is the real deal. After having several other plumbers over, and hearing all the tall plumbing tales of what was causing our problems. Jon showed us what really needed to be done and it was a third of the price with the same guarantees. What a breath of fresh air. Highly recommend him for any plumbing repairs needed. He was fast and courteous. A class act.
- Steve S
a year ago
- Bobby B

About Us

We are a small plumbing company serving the San Antonio and surrounding Metro area including Boerne, New Braunfels and Canyon Lake.  Commercial and residential problems are no more,  if you have had issues other plumbers that could not or would not fix we can help.  If you need backflow tests, repairs, or replacements we can help. Duncan Plumbing specializes in leak detection, re-routes, water heater repairs/replacement, boilers, gas leaks,  advanced troubleshooting and diagnoses,  underground leaks, and almost all other plumbing problems.   We are factory certified to repair most water heaters, and boilers. We have over twenty years experience in the plumbing and backflow business.  We wear boot covers, perform our job as if it was our own home or business, and provide unmatched service and guarantees.  Our technicians are fully licensed and insured.  Call us to schedule your service, we look forward to providing you with competent service. We accept cash, check, and all major credit and debit cards,

Thank You, 
Jon Duncan MP-40679

Complaints may be filed at :  Texas State Board of Plumbing Examiners, PO Box 4200, Austin, TX.  78765  PH: (512)936-5200 ,  Toll Free :  1-800-845-6584

Contact Us


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  • (210) 400-1238

Business Hours

Mon:8:00 AM – 5:00 PM
Tue:8:00 AM – 5:00 PM
Wed:8:00 AM – 5:00 PM
Thu:8:00 AM – 5:00 PM
Fri:8:00 AM – 5:00 PM
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