Expert Tankless Water Heater Repair
Certified Navien tankless service including descaling and error code diagnosis.
Don't wait for a complete breakdown. If you notice any of the following warning signs, it's time to call the experts at Blackmon Plumbing for a professional diagnosis.
Tankless Water Heater Repair — What Every Homeowner Should Know
Signs Your Tankless Water Heater Needs Repair
No hot water or lukewarm water — Heat exchanger failure or gas supply issues require immediate attention
Fluctuating water temperatures — Mineral buildup or failing sensors disrupt consistent heating
Error codes appearing on the display — Digital diagnostics pinpoint exact component failures
Strange noises like banging, rumbling, or whining — Scale buildup or failing internal components
Reduced water flow or pressure — Clogged filters or heat exchanger scaling
Visible leaks or water around the unit — Seal failures or loose connections cause property damage
The unit shuts off unexpectedly — Safety sensors or ventilation problems trigger shutdowns
Our Tankless Water Heater Repair Process
Contact Us & Describe the Issue
Call us or fill out our online form to describe the problem with your tankless water heater. We gather initial details and schedule a convenient appointment time.
Thorough Diagnosis & Upfront Quote
Our MPL-38162 certified technician arrives with diagnostic equipment and performs a comprehensive inspection of your tankless unit. We pinpoint the exact cause of the issue using precision testing tools.
Professional Repair with Quality Parts
Upon your approval, we proceed with the permanent repair. Our fully stocked mobile warehouses carry thousands of Navien parts and specialty tools.
System Testing & Final Verification
After the repair is complete, we thoroughly test your tankless water heater using calibrated instruments. We verify proper operation, safety parameters, and consistent hot water delivery.
Comprehensive Tankless Repair Services
Error Code Diagnosis & Troubleshooting
We decode system error messages instantly. Our diagnostic equipment identifies the exact component failure—no guesswork, no multiple trips. We carry replacement parts for common error codes in our mobile warehouse. One trip. Done.
System Descaling & Flushing Service
We remove mineral buildup that clogs heat exchangers and reduces efficiency. Our industrial-grade descaling equipment restores full water flow and heating capacity. This service extends unit life and prevents costly component damage from scale accumulation.
Flow Sensor & Thermistor Replacement
We replace faulty sensors that cause temperature fluctuations and flow irregularities. Our technicians carry OEM sensors for immediate installation. Precise temperature control returns immediately after sensor replacement.
Igniter and Burner Assembly Repair
We fix ignition failures and flame sensor problems that prevent unit startup. Our mobile warehouse stocks igniter assemblies and burner components. Hot water service resumes the same day with factory-authorized parts.
Annual Maintenance & Tune-Ups
We perform comprehensive system inspections and preventive maintenance. Our service includes descaling, filter replacement, and combustion analysis. Regular maintenance prevents emergency breakdowns and maintains manufacturer warranty coverage.
Complete Unit Replacement
We install new tankless systems when repair costs exceed replacement value. Our technicians handle gas line modifications and venting requirements. Full installation includes permits, code compliance, and manufacturer warranty activation.
Why Choose Blackmon Plumbing?
Certified Navien Service Specialists
We're factory-certified on Navien systems. That means we know every component, every diagnostic sequence, every repair protocol. Your tankless water heater gets expert service from technicians who understand the engineering.
Factory-Trained & Licensed Technicians
Our team holds MPL-38162 — Texas Responsible Master Plumber certification. We complete ongoing factory training on tankless systems. You get technical expertise backed by state licensing.
Fully Stocked 'Mobile Warehouse' Trucks for Faster Repairs
We don't chase parts. We bring them with us. Our mobile warehouse circulating through your area carries Navien components, specialty tools, and diagnostic equipment. One trip. Done.
24/7 Emergency Service Available
No hot water means we dispatch immediately. Our emergency service operates around the clock. We fix it when you need it fixed — not when it's convenient for us.
Upfront, Honest Pricing Before Work Begins
Flat-rate, upfront pricing approved before work begins. No surprises, no hidden fees, no hourly charges that escalate. You know the cost before we touch your system.
Family-Owned & Operated Since 2007
We've served Greater Houston families for over 15 years. Family-owned means we answer for our work. We fix it right because our reputation depends on permanent repair, permanent solution.
Service Areas
From our headquarters in Baytown, TX, we provide prompt and reliable tankless water heater repair services to homeowners and businesses throughout the region. Our mobile warehouse circulates through established service corridors, bringing thousands of parts directly to your location.
We dispatch fully stocked teams across the Ship Channel industrial corridor, covering La Porte and Deer Park where petrochemical facilities demand reliable hot water systems. Manufacturing plants and residential developments in these areas rely on our one-trip repair capability.
Our service territory extends east through Mont Belvieu and the energy corridor, where salt dome storage facilities and growing subdivisions need immediate tankless repairs. We carry specialized parts for commercial-grade units common in industrial applications.
North of the Ship Channel, we serve Crosby and Huffman, where rural properties and newer developments often feature tankless systems requiring expert diagnosis. Our trucks stock components for both residential and light commercial installations.
Contact us for service throughout Harris County and eastern Harris County communities. We fix it. We carry it. We dispatch immediately. MPL-38162 — Texas Responsible Master Plumber ensures every repair meets state standards.
Tankless Water Heater Repair Questions
Annual maintenance prevents 90% of tankless water heater failures. We descale your unit, clean the heat exchanger, and test all sensors during each service visit.
Houston's hard water accelerates mineral buildup inside tankless units. Regular maintenance extends equipment life and maintains peak efficiency. One service call prevents three emergency repairs.
Descaling removes calcium and mineral deposits from your heat exchanger coils. These deposits block water flow and force your unit to overheat.
We pump specialized descaling solution through your system to dissolve buildup. Clean coils heat water efficiently and prevent premature component failure. Descaling restores proper water pressure and eliminates temperature fluctuations.
Units under 8 years old typically benefit from repair. We diagnose the problem and provide flat-rate pricing for both repair and replacement options before starting work.
Our mobile warehouse carries replacement heat exchangers, control boards, and gas valves for same-day repairs. You decide based on upfront costs and remaining equipment life. No pressure, no surprises.
Error codes indicate specific component failures or system malfunctions. We decode manufacturer error messages and carry the exact replacement parts on our trucks.
Common codes signal ignition problems, temperature sensor failures, or gas supply issues. Our diagnostic equipment identifies the root cause immediately. We fix the problem, not just the symptom.
Most repairs complete within 60-90 minutes. We carry common replacement parts like ignitors, sensors, and circuit boards on every service truck.
Complex repairs involving heat exchanger replacement may require 2-3 hours. We provide accurate time estimates after diagnosing your specific problem. One trip. Done.
Other Services You May Need
Water Heater Installation
Full tank water heater installation with code-compliant venting and gas line connections.
View Service →
Water Heater Repair
Same-day diagnosis and repair of gas and electric tank water heaters.
View Service →
Water Heater Replacement
Complete water heater replacement with old unit removal and code-compliant installation.
View Service →
Tankless Water Heater Installation
Navien tankless water heater installation with proper gas line sizing.
View Service →
Tankless Water Heater Replacement
Complete tankless water heater replacement with system upgrade and commissioning.
View Service →
House Repipe
Whole-house repiping to replace failing galvanized or copper pipes with modern PEX.
View Service →
Gas Line Repair
Emergency gas leak repair, line replacement, and red tag clearance.
View Service →
Gas Line Replacement
Complete gas line replacement from meter to appliances with code compliance.
View Service →
Gas Testing
Static pressure testing and gas leak surveys for residential and commercial systems.
View Service →
Backflow Preventer Installation
Professional backflow preventer installation for irrigation, commercial, and fire systems.
View Service →
Backflow Preventer Repair
Same-day repair of failed backflow devices with parts on the truck.
View Service →
Backflow Preventer Testing
Annual state-required backflow testing with documentation submitted to your water authority.
View Service →
Bathroom Remodel
Full-scope bathroom renovation including fixture relocation and new plumbing.
View Service →
Kitchen Remodel
Complete kitchen plumbing renovation for sinks, dishwashers, and gas appliances.
View Service →
Toilet Replacement
Complete toilet replacement with flange inspection, wax ring seal, and supply line upgrade.
View Service →
Water Line Repair
Emergency repair of water supply lines from meter to home.
View Service →
Water Line Replacement
Full replacement of water supply lines with modern materials.
View Service →
Commercial Plumbing Projects
Commercial plumbing for office build-outs, restaurants, and multi-unit properties.
View Service →What Customers Say
"As usual, Shane Blackmon, and his staff are awesome! You could not ask for a better group of people, being led by a man of great integrity. Thank you as my plumber and my friend. I also thank you for all your community..."
"I am so happy I chose Blackmon plumbing. The young lady in the office (Liz) is great at her job. I had my kitchen faucet fixed by the end of the day. I felt like I was an important VIP because of the fast, good service I..."
"Dillion & Mac arrived as scheduled, and professionally installed my new water heater. They were courteous and friendly. They also saved me $60 by accepting a check vs a card. THAT'S total customer service!"
"I had 4 pipes burst and Bret was at my house within the hour and did a great job fixing them at an affordable price. Thanks so much y'all!"
"Bret came out to do the annual service on our tankless hot water heater. The flush went well and our system looked in good shape. Bret knew exactly what was needed, was efficient, and my cost for this I consider to be a ..."
"Blackmon Plumbing connected gas to my home, which was a rather challenging endeavor due to the amount of pipe required to complete the connection. Doday and Mario did an outstanding job. The job required extremely precis..."
"We cannot speak highly enough of Dylan at Blackmon Plumbing! Dylan was incredibly professional, not only with us but also with our tenants, who had been without hot water for two weeks. Despite the challenging circumstan..."
"We are very pleased with the service from Blackmon Plumbing. Dylan and Dodany completed 5 different projects at our home this week. They were knowledgeable, prompt, responsive and courteous. Will use them again."
"Bret and Shane are awesome! Totally recommend them for plumbing!"
"Scott did a great job fixing my toilet. Would definitely recommend Blackmon."
"Brett and Leo were here. They were professional, efficient and friendly and did a great job in less time than expected. Hope they will both be back if we decide to install a new water heater."
"Came as soon as we needed them. Thought we needed a new water heater, but because of their honesty found out it was just a part needed. Thanks to Scott and Julio for a great job!"
"I had a wonderful experience with Blackmon Plumbing. Dylan arrived right on time. He was very polite, professional, knowledgeable and a hard worker! He had to haul an old toilet down the stairs and a new one up the stair..."
"We had a gas leak we needed found and fixed. They were able to fix it quickly with no hassle. Prices were fair! Would definitely do more business with them again."
"I had my kitchen faucet replacement last week and am very satisfied with Blackmon’s services. They only charged me one hour labor at a very reasonable price compared with other plumbing companies that tried to charge me ..."
"This company is fantastic. Shane and Laurie are very professional and a pleasure to do business with. I would highly recommend this to everyone."
"Very thorough and polite. Most importantly, they can be trusted. Yes, there are still plumbers with integrity who take pride in their work. Back-up generator installation was quick and done well."
"The folks at Blackmon have a customer first attitude. They do what they say and say what they do. Michael came by after the job was completed to double check that all is well. 5 plus stars are earned and their business d..."
"Wow! I don't usually leave reviews, but what a great overall experience from Blackmon Plumbing! My faucet had a leak requiring replacement. They did such a great job installing my gorgeous new sink! I loved the customer ..."
"Fast install and good price, but don't appreciate them leaving trash and old fittings in the attic. Sloppy craftsmanship."