Can I replace my own tankless water heater?

Author: scraper  |  Last update: Sunday, September 27, 2026

Yes, you can replace a tankless water heater yourself, but it is a complex, multi-trade project involving advanced plumbing, gas fitting, and electrical work. For safety and code reasons, many municipalities require a licensed professional, and DIY installation will void most manufacturer warranties.

Can a homeowner install their own tankless water heater?

While technically possible if you have advanced DIY skills, installing a tankless water heater yourself is not recommended for beginners. It involves complex plumbing, specialized electrical work, and dangerous gas fitting.

Why do plumbers not recommend tankless water heaters?

Plumbers often hesitate to recommend tankless water heaters due to their steep upfront costs, rigorous annual maintenance requirements (such as flushing to prevent mineral buildup), and complex installation. Furthermore, homes often require costly electrical or gas infrastructure upgrades to accommodate these high-demand units.

Is it hard to replace a tankless hot water heater?

Replacing a tankless water heater is a moderately difficult to complex project, generally considered a 5 to 8-hour job. Because it involves potentially hazardous elements like high-voltage electricity, gas lines, and venting, doing it yourself is only recommended if you are highly experienced with home plumbing and electrical.

What's the average cost to replace a tankless water heater?

Replacing a tankless water heater costs between $2,500 and $5,500 on average, including both the unit and professional installation. Depending on the complexity of the job, size of the home, and local labor rates, prices can range from $1,500 on the low end for small electric units, up to $8,000+ for complex whole-home gas system upgrades.

How to Install a Tankless Gas Water Heater | The Home Depot with @thisoldhouse

What is the downside of a tankless water heater?

The main downsides of a tankless water heater are their significantly higher upfront costs, limited hot water flow during simultaneous usage (e.g., showering and running a dishwasher at the same time), and the need for costly annual flushing to prevent mineral buildup in hard water areas.

How much does Home Depot charge to replace a tankless water heater?

Depending on your selection, the average cost for standard tank installation is generally between $1,600 to $2,400. Tankless installation can range from $2,400 to $5,400.

What is the lifespan of a tankless water heater?

A tankless water heater typically lasts 15 to 20 years—nearly double the lifespan of traditional tank models. With diligent maintenance and high-quality water, some units can even reach 20 to 30 years of service.

Which is better, Navien or Rheem?

Navien and Rheem are both premier choices for tankless water heaters, but they excel in different areas: Navien is the premium choice for advanced features and high energy efficiency, while Rheem is the better option if you want reliable, budget-friendly performance.

Can you run two showers with a tankless water heater?

Yes, you can run two showers at the same time, but it completely depends on your tankless heater's flow rate (GPM) and the groundwater temperature in your area.

Can pipes burst with a tankless water heater?

Yes, pipes can absolutely burst with a tankless water heater. While tankless units themselves do not have large storage tanks that rupture from pressure, the external supply and exit pipes, as well as the unit's internal heat exchanger, are highly susceptible to freezing.

Is there an IRS tax credit for a tankless water heater?

Yes, you can claim a federal tax credit for qualifying tankless water heaters. Under the Energy Efficient Home Improvement Credit (Section 25C), you can get 30% of the total installation cost (including labor), up to a maximum credit of $600.

What is the most common problem with tankless water heaters?

The most common problem with tankless water heaters is mineral scale buildup (calcium and magnesium) inside the heat exchanger. This happens when hard water is heated, causing efficiency drops, restricted water flow, and frequent error codes. Regular descaling is required to prevent this.

How long will a 100lb propane tank run a tankless water heater?

A 100lb propane tank holds approximately 23.6 gallons of usable propane. Depending on your hot water usage and groundwater temperature, this tank will run a tankless water heater for about 30 to 60 hours of continuous burn time.

Can a handyman legally replace a water heater?

Whether a handyman can legally replace a water heater depends entirely on your local city and state regulations. In many jurisdictions, a licensed plumber or electrician is required by law, while others allow a handyman to do a simple "swap-out" if no major gas or electrical modifications are needed.

How much does Lowes charge to install a water heater?

Lowe's typically charges between $300 and $800 in base labor fees to install a standard water heater. However, your total out-of-pocket cost will range from $1,000 to $2,500+, because Lowe's requires you to buy the unit, delivery, and installation together as a package.

Which company makes the best tankless water heaters?

The "best" tankless water heater depends on your setup, but Rinnai and Navien are widely regarded as the top tier for gas units, while Stiebel Eltron and EcoSmart lead for electric.

Where does Rheem rank?

Rheem is widely considered a top-tier HVAC and water heating brand, frequently ranking in the top 5 to 10 overall HVAC brands. It is highly regarded by industry experts for its excellent reliability, affordable mid-tier pricing, and contractor-friendly designs.

Where are Navien heaters made?

Navien tankless water heaters and boilers are primarily manufactured at the company’s massive, state-of-the-art facility in Seotan, South Korea. Navien also operates an assembly and distribution plant in Toano (James City County), Virginia, to better serve the North American market.

Why are plumbers against tankless water heaters?

Plumbers aren't inherently against tankless water heaters, but they often steer clients toward traditional tanks because tankless units are expensive to install, require significant home modifications, and demand strict, costly annual maintenance to avoid voiding warranties.

How much does a tankless water heater raise your electric bill?

An electric tankless water heater generally adds about $15 to $45 per month to your electric bill, depending on your household size and local utility rates. Because they only heat water on-demand rather than maintaining a constant reservoir, they typically reduce energy consumption and can be 24% to 34% more efficient than traditional tanks.

Do tankless water heaters break down often?

A typical tankless water heater's lifespan often ranges from 15 to 20 years or more with proper care. In many cases, well-maintained systems can reach 25 to 30 years of service. That extended lifespan is one of the strongest considerations for homeowners researching how to choose a tankless water heater.

How much should a plumber charge to install a tankless water heater?

Labor to install a tankless water heater typically costs $600 to $1,850, depending on your home's setup, local plumber rates ($45–$200/hour), and job complexity. Factoring in the unit itself, materials, and permits, expect a total installed cost of $2,400 to $5,400.

Does Home Depot haul away old water heaters?

What's included in a water heater installation? A hot water heater replacement consists of: Delivery of your new water heater and haul away of old unit. Disconnect and removal of existing water heater.

Are there tax credits for tankless heaters?

This tax credit comes from the 25C Energy Efficient Home Improvement Tax Credit program. It's designed to help people save money when they upgrade to more efficient home equipment. Your gas tankless water heater needs to meet certain efficiency standards and have ENERGY STAR® certification to qualify.

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