How to Install a Tankless Water Heater and When to Call a Pro

Tankless water heaters offer an efficient way to enjoy hot water on demand without the bulk of traditional tanks. They save space, reduce energy costs, and provide endless hot water. But installing a tankless water heater requires careful planning and some technical know-how. This guide walks you through how to install a tankless water heater and helps you decide when it’s best to hire a professional.

Let’s start!

Understanding Tankless Water Heaters

Tankless water heaters, also called on-demand heaters, heat water only when you need it. Unlike traditional water heaters that store hot water in a tank, these units heat water as it flows through the device. This means you don’t run out of hot water, and you avoid the energy loss that comes with keeping a tank full of hot water.

They come in electric and gas models, each with different installation requirements. Knowing which type fits your home and needs is the first step before installation.

When to Choose a Tankless Water Heater

Tankless water heaters suit households that want to:

• Save space with a compact unit mounted on a wall

• Reduce energy bills by heating water only when needed

• Have a continuous supply of hot water for large families or frequent use

• Upgrade from an old, inefficient water heater

  
  

If your home has low water pressure or multiple bathrooms running at once, a tankless system can handle the demand better than a traditional tank.

Tools and Materials Needed for Installation

Before starting, gather the following:

• Tankless water heater unit (electric or gas)

• Mounting hardware and brackets

• Pipe fittings and connectors (copper, PVC, or PEX depending on your plumbing)

• Pipe cutter and wrench

• Teflon tape and pipe sealant

• Electrical wiring and circuit breaker (for electric models)

• Gas line and shutoff valve (for gas models)

• Venting materials (for gas models)

• Pressure relief valve

• Water shutoff valves

• Drill and screwdriver

• Safety gear (gloves, goggles)

  
  

Having everything ready helps the installation go smoothly.

Step-by-Step Installation Process

1. Turn Off Utilities

Start by shutting off the main water supply and power source. For gas models, turn off the gas supply. This prevents accidents during installation.

2. Remove the Old Water Heater

Drain and disconnect your existing water heater. Carefully detach water lines, electrical connections, and gas lines if applicable.

3. Choose the Installation Location

Select a spot near existing plumbing and power or gas lines. The location should allow proper venting if you have a gas model. Wall mounting is common for tankless units.

4. Mount the Tankless Unit

Use the mounting hardware to secure the unit to the wall. Make sure it is level and firmly attached to support the weight.

5. Connect Water Lines

Attach the cold water inlet and hot water outlet pipes to the unit. Use Teflon tape and pipe sealant to prevent leaks. Check local codes for pipe material requirements.

6. Install Pressure Relief Valve and Shutoff Valves

Add a pressure relief valve to protect the unit from excess pressure. Install shutoff valves on both water lines for easy maintenance.

7. Connect Gas or Electrical Supply

• For gas models, connect the gas line with a shutoff valve and ensure proper venting to the outside.

• For electric models, wire the unit to a dedicated circuit breaker following the manufacturer’s instructions.

  
  

8. Test the System

Turn on the water supply and check for leaks. Restore power or gas and run hot water through the system. Verify the unit heats water properly and the pressure relief valve functions.

When to Hire a Professional

Installing a tankless water heater involves detailed plumbing, electrical, and often gas work, which is why hiring a licensed professional like The Handyman San Diego is one of the smartest choices you can make for your home. If you don’t have experience with plumbing or electrical systems, need new gas lines or venting installed, are required to get local permits and inspections, or want to ensure safety and full warranty coverage, a professional installer can handle the job correctly. Experts can manage complex installations, troubleshoot issues, and guarantee that your system meets all codes and regulations. 

The benefits of professional installation include proper sizing and placement of the unit, safe and code-compliant gas and electrical connections, correct venting to prevent carbon monoxide buildup, faster installation with fewer mistakes, and access to manufacturer warranties and support. In addition to tankless water heater installation, The Handyman San Diego provides a full range of home improvement services — from durable flooring installation and precision drywall repair to home exterior upgrades and more — delivering exceptional quality and reliability for all your home projects. 

Maintenance Tips for Tankless Water Heaters

To keep your system running efficiently:

• Flush the unit annually to remove mineral buildup

• Check and clean filters regularly

• Inspect venting and gas lines for leaks

• Schedule professional inspections every few years

  
  

Regular maintenance extends the life of your heater and maintains performance.

Conclusion

Installing a tankless water heater is an excellent way to save space, improve energy efficiency, and enjoy continuous hot water in your home. While experienced homeowners may be able to handle certain aspects of the installation, the complexity of plumbing, electrical, and gas connections makes professional service the safest and most reliable option. For expert installation done right the first time, trust The Handyman San Diego.

Contact us today to schedule your tankless water heater service and ensure lasting performance and peace of mind.

Frequently Asked Questions

Is a tankless water heater better than a traditional tank system?

Tankless water heaters are generally more energy-efficient, take up less space, and provide endless hot water, making them a popular upgrade for many homeowners.

Can I install a tankless water heater myself?

While it’s possible for highly skilled DIYers, professional installation is recommended due to the need for proper gas, electrical, plumbing connections, and code compliance.

How long do tankless water heaters last?

With proper maintenance, tankless water heaters can last 20 years or more, which is often longer than traditional tank systems.

Do tankless water heaters increase home value?

Yes, they can increase home value by improving energy efficiency and appealing to buyers looking for modern, cost-saving upgrades.