Your water heater headquarters. Tank, tankless, gas, and electric repair, replacement, and maintenance by Navien-certified, veteran-owned technicians. Flat-rate pricing. No surprises.
Your Water Heater HQ
Whether your hot water ran out this morning, your unit is leaking, or you're ready to upgrade to a tankless system, O5 Plumbing handles it all. We're certified by Navien one of the leading tankless water heater manufacturers and we service every major brand of tank and electric system too.
Universal City's hard water takes a toll on water heaters faster than most homeowners realize, especially in the neighborhood's established 1990s and 2000s subdivisions. Sediment builds up on heating elements, anode rods corrode, and efficiency drops often years before the system finally fails. We diagnose the real issue first, then give you options at a flat price.
Annual maintenance extends the average water heater lifespan by 3-5 years and maintains peak energy efficiency year-round.
Gas Water Heaters
Tank and tankless gas systems repair, replacement, and new installs
Electric Water Heaters
Element replacement, thermostat repair, and full replacements
Tankless / On-Demand
Navien-certified installs. Endless hot water, lower energy bills
Annual Maintenance
Flush, anode rod inspection, and efficiency check all brands
What We Do
No cold water when you need it most, discolored water, strange noises, or a puddle under the tank we diagnose it right, give you a flat quote, and fix it the same day when possible.
When repair isn't the right answer, we help you choose the best system for your household's hot water usage and budget conventional tank or tankless. Pro-grade units with manufacturer warranties.
Navien-certified installation of on-demand systems. Tankless units produce hot water only when needed no standby heat loss, no 40-gallon tank to run dry, and a significantly longer lifespan than conventional units.
Know Your Options
Not sure which is right for your home? We'll assess your household size, usage, and existing setup then give you a straight recommendation.
Why O5
O5 is the only Navien-certified plumber in the Universal City area you'll find that also does flat-rate pricing. That means you get the expertise of a manufacturer-trained technician and the assurance of knowing the number before we pick up a single tool.
We also don't sell you a new unit when a repair will do. If your water heater has life left in it, we'll tell you and fix it for less than a replacement.
Request a QuoteFactory-trained on the leading tankless systems proper sizing, install, and diagnostics.
Accountability and integrity on every job the same standards we held ourselves to in service.
After the scope is clear, you approve the quote before work begins. No hourly billing that climbs while we work.
Same-day service when available. When your hot water goes out, we don't make you wait until next week.
Current Coupons
Mention your coupon when you call. One coupon per visit and cannot be combined with other offers.
Get Your Quote
Within 24 Hours
Request a plumbing quote and the O5 team will follow up within 24 hours.
$175 Off
Water Softener
Save on qualifying whole-home water softener service or installation.
$75 Off
Water Heater
Save on qualifying water heater repair, replacement, or installation.
Free
2nd Opinion
Get a second opinion before approving major plumbing work.
$25 Off
Drain Cleaning
Save on qualifying kitchen, bathroom, or main line drain cleaning service.
Terms: One coupon per service visit. Coupons cannot be combined with other offers or applied to prior service calls. Discounts apply to labor only unless otherwise noted. Call (830) 293-4141 to confirm current availability.
Customer Reviews
"O5 installed a Navien tankless water heater to replace our old tank unit. The process was smooth, the price was exactly what they quoted, and the difference in hot water availability is night and day. Professional crew, clean installation."
Jennifer A.
Universal City • Tankless Install
"Had low pressure issues throughout the house. O5 came out, diagnosed a failing PRV within 30 minutes, replaced it same day, and explained exactly what was happening. Fast, fair, and straight to the point. These are my plumbers now."
Mark D.
Universal City • PRV Replacement
"Whole-home softener and RO system for our kitchen. The tech was knowledgeable, the installation was clean, and they followed up to make sure everything was working correctly. Veteran-owned business you can tell they actually care."
Sarah N.
Universal City • Softener & RO Install
Common Questions
Ready?
Call us and we'll diagnose the issue, give you options, and get it handled often the same day. Ask about current coupons and financing.
Mon-Fri 7:30 AM - 6:00 PM • Sat 8:00 AM - 5:00 PM • Same-day service when available