How Much Does Tankless Water Heater Repair Cost in 2025?

This article was created using automation technology and thoroughly fact-checked and edited by HomeAdvisor Editor Ryan Noonan.

Tankless water heater repairs cost an average of $600 or between $75 and $1,300. More complex or involved repairs may cost up to $1,950. Technicians charge between $45 and $200 per hour, depending on your location and the complexity of service needed. Regular maintenance not only ensures efficient operation but can extend your unit's lifespan to approximately 20 years.

Tankless Water Heater Repair Cost Factors

The cost to repair a tankless water heater varies depending on the type of repair, local labor rates, and several other factors.

Type of Repair

Tankless water heaters have numerous components that vary in complexity. Certain replacement parts can cost more outright to purchase, while others may have more involved labor needs. 

Minor Repairs: Fuse, Leak, Pilot Light

Simple repairs like fuse replacement cost between $50 and $75, while pilot light issues run $75 to $150. Pipe-related repairs can range from $100 to $350 depending on complexity and accessibility.

Major Repairs: Heat Exchanger, Gas Valve

More significant issues require more extensive service. Gas valve replacement averages approximately $350, while substantial repairs for leaks can approach $1,000 in complex situations.

Labor

Plumbers charge more in metropolitan areas than in rural locations. Hourly rates range from $45 for basic service to $200 for specialized work. Emergency service outside regular business hours may incur premium rates, potentially pushing your maintenance costs toward the upper end of the range.

Location

Labor rates and costs for replacement parts vary by region. Here are average service costs you can expect for different cities.

Brand and Part Availability

Water heater brands vary in component quality and availability. Systems with readily available parts cost less to maintain than those requiring special-order components. When specialized parts are needed, service costs may approach the higher end of the maintenance spectrum.

Water Hardness 

Regions with hard water require more frequent maintenance as mineral deposits accumulate faster in the system. Homeowners in these areas may need bi-annual rather than annual service, potentially doubling the yearly maintenance expense for proper descaling treatments.

Usage

Systems in homes with high hot water demand experience more operational cycles, potentially requiring more frequent maintenance. Conversely, units in vacation properties or homes with minimal usage may need less intensive service, keeping costs closer to the lower end of the price range.

Additional Repair Costs

Tankless water heaters also require these maintenance tasks periodically.

Flushing and Descaling

During this essential procedure, technicians connect specialized equipment to remove mineral buildup from internal components. Professional flushing services cost between $150 and $300, with prices varying based on system complexity and local rates.

Cleaning or Replacing Filters

Regular filter maintenance helps prevent system inefficiency and component damage. During annual service visits, technicians will inspect and clean existing filters or recommend replacement when necessary.

Checking Connections and Valves

Professional maintenance includes thorough inspection of all water and gas connections, ensuring proper function of the pressure relief valve and other safety components. Replacing a pressure relief valve costs between $75 and $150 if issues are detected.

Repair vs. Replacement

Repair is a cost-effective strategy if your system is under 10 years old and hasn't had any other major issues or breakdowns. Prompt repairs can keep your system running for 20 years or more.

Consider replacing your tankless water heater if repair costs exceed half the price of a new system, especially for units over 15 years old. Declining efficiency despite regular maintenance, frequent error codes, or persistent leaks also suggest replacement may be more economical than continued repairs.

DIY Tankless Water Heater Repair vs. Hiring a Pro

Performing basic maintenance yourself can reduce service costs but requires proper knowledge and equipment. DIY maintenance carries risks including potential warranty invalidation and personal safety concerns, especially with gas-powered systems.

Most manufacturers require documentation of professional maintenance to maintain warranty coverage. Before attempting DIY service, review your warranty terms carefully to avoid potentially costly coverage issues. When in doubt, hire a local water heater repair contractor or plumber to keep your unit running safely and efficiently.

Budgeting for Tankless Water Heater Repair Cost

Use these tips to help you save on tankless water heater repair costs:

• Schedule annual inspections: A consistent maintenance schedule helps prevent costly emergency repairs and extends system lifespan. Consider maintenance contracts for potentially reduced rates on annual service.

• Install a water softener: In hard water regions, installing a water softening system can reduce scale buildup, decreasing the frequency of required maintenance.

• Schedule off-peak service: Booking maintenance during standard business hours and less busy seasons can help avoid premium rates associated with emergency or after-hours service.

How HomeAdvisor Gets Its Cost Data

No place is more important than your home, which is why HomeAdvisor connects homeowners with local pros to transform their houses into homes they love. To help homeowners prepare for their next project, HomeAdvisor provides readers with accurate cost data and follows strict editorial guidelines. After a project is complete, we survey real customers about the costs to develop the pricing data you see, so you can make the best decisions for you and your home. We pair this data with research from reputable sources, including the U.S. Bureau of Labor Statistics, academic journals, market studies, and interviews with industry experts—all to ensure our prices reflect real-world projects.