Does a Plumber or Electrician Install a Tankless Water Heater?

Thinking about upgrading to a tankless water heater but unsure who to call? You’re not alone. Many homeowners ask: “Does a plumber or electrician install a tankless water heater?” The answer isn’t always straightforward—because both professionals may be needed, depending on your unit type and home setup. In this guide, we’ll break down exactly who does what, why it matters, and how to avoid costly mistakes.

Who Installs a Tankless Water Heater: Plumber or Electrician?

The short answer: It depends on whether your tankless water heater runs on gas or electricity.

• Gas-powered tankless units require a licensed plumber (or HVAC technician in some states) for gas line and venting work.
• Electric tankless units need a licensed electrician to handle high-voltage electrical connections.
• In many cases—especially during full replacements—you’ll need both.

According to the U.S. Department of Energy, tankless water heaters can be 24–34% more energy-efficient than conventional storage tanks for homes using 41 gallons or less of hot water daily. But that efficiency only pays off if installed correctly by qualified professionals.

Gas vs. Electric Tankless Water Heaters: Who Handles What?

🔧 Gas Tankless Water Heaters

These units use natural gas or propane and require:

• Gas line installation or modification
• Proper venting through walls or roofs
• Water line connections
• Compliance with local gas codes

✅ Primary installer: Licensed plumber
In many states, plumbers are certified to handle gas lines and venting. Some regions require an HVAC technician for combustion-related work, so always check local regulations.

“Improper gas line sizing or venting can lead to carbon monoxide leaks—a serious health hazard,” warns the National Fire Protection Association (NFPA) .

⚡ Electric Tankless Water Heaters

These run on electricity and often demand:

• A dedicated 240-volt circuit
• Upgraded electrical panel capacity (many require 100+ amps)
• Proper grounding and breaker installation

✅ Primary installer: Licensed electrician
Electric tankless heaters can draw up to 150 amps, far exceeding standard household circuits. Only a qualified electrician should handle this load to prevent fire risks or panel damage.

💡 Pro Tip: Before buying an electric model, have an electrician assess your panel. Upgrading it can cost $1,000–$3,000, potentially making a gas unit more economical.

Why You Might Need Both a Plumber and an Electrician

Even if you choose a gas unit, you may still need an electrician—because most modern tankless heaters require electricity to power:

• Digital control panels
• Ignition systems
• Flow sensors

Similarly, an electric unit still connects to your plumbing system, so a plumber may be needed for:

• Shut-off valves
• Water pressure regulators
• Pipe rerouting

Real-World Example: In a 2023 HomeAdvisor survey, 68% of tankless water heater installations involved both plumbing and electrical professionals. Skipping one led to 32% of callbacks for repairs or code violations.

Step-by-Step: How a Professional Installation Works

Here’s what a typical tankless water heater installation looks like when done right:

1. Assessment (Day 1)
   • Plumber checks gas line size, water pressure, and venting options.
   • Electrician evaluates panel capacity and circuit availability.
2. Permit Acquisition
   • Most municipalities require permits for gas/electrical modifications. Professionals handle this paperwork.
3. Installation (Day 2–3)
   • Plumber: Installs gas line (if needed), mounts unit, connects water lines, sets up venting.
   • Electrician: Runs new 240V circuit, installs double-pole breaker, wires control panel.
4. Testing & Inspection
   • Both pros test for leaks, proper ignition, and electrical safety.
   • Local inspector verifies code compliance.
5. Final Walkthrough
   • You receive operation instructions and warranty documentation.

⚠️ Never DIY: The International Association of Certified Home Inspectors (InterNACHI) reports that 70% of DIY tankless heater issues stem from improper gas or electrical work.

Plumber vs. Electrician: Quick Comparison

Note: Always verify local licensing rules—some states allow cross-certification.

Common Mistakes Homeowners Make

Avoid these pitfalls that lead to inefficiency, damage, or safety hazards:

• Assuming one pro can do it all → Leads to incomplete installations.
• Skipping permits → Can void home insurance or cause issues during resale.
• Ignoring water hardness → Tankless units are sensitive to mineral buildup. Install a water softener if your area has hard water (above 7 grains per gallon).
• Oversizing the unit → A 9.5 GPM unit for a 1-bathroom home wastes energy. Use the DOE’s sizing guide to match flow rate to your needs.

FAQ: Your Top Questions Answered

Q1: Can a handyman install a tankless water heater?

A: Generally, no. Most states require licensed plumbers or electricians for gas and high-voltage electrical work. Handymen often lack the certification for these tasks, and doing so illegally can void your warranty or insurance.

Q2: How much does professional installation cost?

A:

• Gas tankless: $1,200–$3,500 (includes venting and gas line)
• Electric tankless: $800–$2,000 (plus potential panel upgrade)
  Costs vary by region, unit size, and home complexity. Always get 3+ quotes.

Q3: Do tankless water heaters need maintenance?

A: Yes! Annual flushing is critical to remove mineral deposits. Plumbers typically charge $100–$150 for this service. Neglecting it can reduce efficiency by up to 30% over time.

Q4: Can I switch from a tank to tankless myself?

A: Strongly discouraged. The U.S. Consumer Product Safety Commission links improper water heater installations to hundreds of carbon monoxide incidents yearly. Leave it to licensed pros.

Q5: Are permits really necessary?

A: Yes. Permits ensure your installation meets the International Plumbing Code (IPC) and National Electrical Code (NEC). Skipping them risks fines, failed inspections, or liability in case of accidents.

Q6: What’s the lifespan of a tankless water heater?

A: With proper installation and maintenance, most last 20+ years—nearly double that of traditional tanks. Source: U.S. Department of Energy .

Conclusion: Safety, Efficiency, and Peace of Mind

So, does a plumber or electrician install a tankless water heater? The smart answer is: whichever (or both) your system requires. Cutting corners might save a few dollars upfront—but risks safety, efficiency, and long-term savings.

By hiring qualified professionals, you ensure:

• Code-compliant, safe operation
• Maximum energy savings
• Full warranty coverage
• Longer system life

👉 Found this guide helpful? Share it with a friend who’s upgrading their water heater! And if you’re ready to install, always request proof of license, insurance, and references before hiring.

Your comfort—and safety—is worth the right expert.