Expert installation, repair, and maintenance of on-demand water heaters — endless hot water, lower energy bills, and space-saving design.
Tankless water heaters (also called on-demand water heaters) provide endless hot water while using up to 30% less energy than traditional tank models. Whether you're looking to upgrade from a conventional water heater or need repair on your existing tankless system, LEX Air Conditioning has the expertise to help.
Our licensed plumbing technicians specialize in tankless water heater installation, repair, maintenance, and replacement throughout the Dallas-Fort Worth metroplex. We work with all major brands including Rinnai, Navien, Rheem, Noritz, Takagi, and more. With over 22 years of experience and thousands of satisfied customers, we're the trusted choice for tankless water heater services in DFW.
Comprehensive solutions for all your tankless water heater needs.
Professional installation of new tankless water heaters. We'll help you choose the right size and model for your home's hot water demands, install it to code, and ensure optimal performance from day one.
Fast, reliable repairs for all tankless water heater problems. From error codes and ignition failures to low water pressure and inconsistent temperatures, we diagnose and fix issues quickly.
Regular maintenance extends your tankless water heater's lifespan and efficiency. We perform descaling, flush the system, check components, and clean filters to prevent buildup and ensure peak performance.
Upgrading from a traditional tank water heater? We'll assess your home's gas line capacity, electrical requirements, and venting needs, then handle the complete conversion to tankless.
If your existing tankless unit is beyond repair or outdated, we'll recommend the best replacement option and install it efficiently. We remove your old unit and recycle it responsibly.
Not sure if your tankless water heater is working properly? We offer comprehensive inspections to assess performance, identify issues, and recommend repairs or upgrades if needed.
Tankless water heaters offer significant advantages over traditional tank models.
Never run out of hot water again. Tankless units heat water on demand, providing continuous hot water for showers, laundry, dishes, and more — even during peak usage times.
Save up to 30% on water heating costs. Tankless heaters only heat water when you need it, eliminating standby heat loss from constantly reheating a tank full of water.
Tankless units are compact (about the size of a carry-on suitcase) and mount on walls, freeing up valuable floor space in your utility room, garage, or closet.
Tankless water heaters last 20+ years with proper maintenance — nearly twice as long as traditional tank models that typically last 10-12 years.
Because there's no storage tank, you eliminate the risk of catastrophic tank failure and flooding that can cause thousands in water damage to your home.
Energy Star-rated tankless models can save the average household $100-150 per year on utility bills compared to standard tank water heaters.
Don't ignore these warning signs — early detection can save you money and prevent bigger problems.
If your water temperature fluctuates between hot and cold, or you're getting lukewarm water instead of hot, your tankless unit may have a faulty heating element, mineral buildup, or sensor issues.
Tankless water heaters display error codes when something's wrong. Common codes indicate ignition failure, flame failure, overheating, or airflow problems. Don't ignore these — call for service.
If hot water flow is weaker than normal, you may have scale buildup inside the heat exchanger, a clogged filter, or a failing flow sensor that needs professional attention.
If your tankless heater won't turn on or ignite, it could be a gas supply issue, electronic ignition failure, venting problem, or sensor malfunction. This requires immediate professional diagnosis.
Unusual rumbling, whistling, or popping sounds often indicate mineral buildup. A sulfur or rotten egg smell could mean a gas leak — evacuate and call us immediately.
While tankless units don't have large tanks that can burst, they can still develop leaks at connections, valves, or the heat exchanger. Any leak should be addressed promptly to prevent water damage.
Noticing any of these issues? Don't wait until it becomes an emergency.
Call for Same-Day ServiceWhat to expect when you call LEX for tankless water heater services.
Call us at (972) 466-1917 or book online. We'll ask about your water heater issue or installation needs, confirm a convenient appointment time, and dispatch a licensed plumber — often same-day for repairs and emergencies.
Our technician arrives on time in a fully stocked truck, diagnoses your tankless water heater issue, and provides upfront pricing before any work begins. For installations, we'll assess your home's requirements and recommend the right model and size.
With your approval, we complete the installation, repair, or maintenance using quality parts and proven techniques. Most repairs are done in one visit. Installations typically take 4-8 hours depending on complexity.
We test your tankless water heater to ensure proper operation, walk you through the controls and features, provide maintenance tips, clean up our work area, and answer any questions you have.
Same-day service available with 15-25 minute response times across DFW. We know water heater issues can't wait, especially in Texas winters.
You'll know the cost before we start. No hidden fees, no surprises — just honest, transparent pricing for repairs, installations, and maintenance.
Our technicians are fully licensed (M-18088), insured, and background-checked. We hire the best plumbers in DFW so you get expert service every time.
We repair, install, and service all major tankless water heater brands including Rinnai, Navien, Rheem, Noritz, Takagi, Bosch, Bradford White, and more.
We stand behind our work with a 100% satisfaction guarantee. If you're not happy with our service, we'll make it right — that's our promise.
We're not a franchise or a big corporation. We're your neighbors at 901 Jupiter Rd in Plano, serving DFW families and businesses for 22+ years.
"We had LEX install a Rinnai tankless water heater to replace our old 40-gallon tank, and it's been amazing. No more running out of hot water during morning showers, and our energy bill dropped noticeably. The installation crew was professional, clean, and explained everything. Highly recommend!"— Jennifer M., Frisco, TX
We believe in transparent pricing. While every situation is different, here's what you can expect for tankless water heater services:
*Prices are estimates and may vary based on specific conditions, unit size, venting requirements, and gas line modifications. We always provide upfront pricing before starting work.
Every home and situation is different. Call us for a free diagnosis and upfront quote for your tankless water heater service — no obligation.
(972) 466-1917Financing available with approved credit
Our technicians are trained to work on all major tankless water heater brands.
Don't see your brand? We service all makes and models. Call us to confirm.
We provide tankless water heater installation, repair, and maintenance throughout the Dallas-Fort Worth metroplex.
We offer complete plumbing solutions for your home.
With proper maintenance, tankless water heaters typically last 20+ years — nearly twice as long as traditional tank models (10-12 years). Annual descaling and filter cleaning are essential to maximize lifespan, especially in areas with hard water like DFW.
Sizing depends on your home's peak hot water demand (how many fixtures run simultaneously) and the temperature rise needed. A typical 3-bathroom home needs a unit rated for 7-10 gallons per minute (GPM). Our technicians will assess your usage and recommend the right size during the consultation.
Yes, if properly sized. A whole-home tankless unit rated for 9-11 GPM can typically handle 2-3 simultaneous showers plus other fixtures. For larger homes with high demand, we may recommend multiple units or a high-capacity model.
Installation costs range from $2,500 to $4,500 depending on the unit size, venting requirements, gas line modifications, and whether electrical upgrades are needed. Converting from a tank to tankless may require additional work like running new gas lines or upgrading to a larger gas meter. We provide detailed upfront quotes.
We recommend annual maintenance, including descaling (flushing with vinegar solution to remove mineral buildup), filter cleaning, and component inspection. In areas with very hard water, descaling every 6-9 months may be necessary. Regular maintenance prevents costly repairs and maintains efficiency.
Yes. Tankless units are 24-34% more efficient than tank models because they only heat water on demand, eliminating standby heat loss from keeping 40-50 gallons hot 24/7. Energy Star estimates savings of $100-150 per year for a typical household, with payback in 5-10 years depending on usage and energy costs.
Fast, reliable service from a licensed plumber you can trust. Call today or book online.
Serving DFW since 2004 • 2,000+ 5-Star Reviews • Licensed Plumber M-18088
