How to Install a Tankless Water Heater: An Easy Step-by-Step Guide In 2024

how to install a tankless water heater

Have you ever wondered how to install a tankless water heater the right way? Installing a tankless water heater in your home can offer numerous benefits, such as energy savings, continuous hot water supply, and more efficient use of space.

Unlike traditional water heaters with large tanks, these compact units heat water directly as it flows through the device, ensuring you don’t pay to heat water you aren’t using. Before embarking on the installation process, it’s important to understand that this task can be complex and may require a certain level of technical expertise.

The installation of a tankless water heater involves several key steps—from preparing for the switch by removing your old water heater to mounting the new device and ensuring it’s properly connected to your utilities.

Attention to detail is crucial, especially when it comes to safely venting the unit and making certain it meets all local building codes and regulations.

Once everything is installed, system testing and calibration are essential to verify that your tankless water heater functions correctly before you begin regular use.

Key Takeaways For How To Install A Tankless Water Heater

  • Tankless water heaters provide energy efficiency and a constant supply of hot water.
  • A successful installation requires several steps, including proper mounting and connection.
  • Safety and compliance with regulations are paramount throughout the installation process.

Understanding Tankless Water Heaters

Before opting to install a tankless water heater, it’s important to recognize their benefits, understand the different types available, and determine the size that will efficiently meet your hot water needs.

Benefits of Tankless Water Heaters

Tankless water heaters, often referred to as on-demand water heaters, provide hot water only as it is needed. This approach can lead to energy savings, as they don’t produce the standby energy losses associated with storage water heaters.

Additionally, many find that tankless water heaters offer a continuous supply of hot water—which is particularly advantageous for large families or those with high hot water usage.

Types of Tankless Water Heaters

The two key types of tankless water heaters are condensing and non-condensing. Condensing units are typically more energy efficient as they capture heat from the exhaust gases and use it to heat the water, which can be reflected in a recent Minnesota field study.

Non-condensing units are more common and usually less expensive upfront, but they don’t utilize this additional heat, making them slightly less efficient overall.

Sizing Your Tankless Water Heater

To size a tankless water heater, it’s necessary to calculate the maximum flow rate you’ll need at any one time (measured in gallons per minute, GPM) and the desired temperature rise. The flow rate is the sum of all water fixtures running simultaneously.

A Study on water heater performance can help in understanding these requirements for various household sizes and water usage patterns. Proper sizing is crucial as it ensures that you’ll never run out of hot water and that your heater won’t be overtaxed.

Preparing for the Tankless Water Heater Installation

When you’re getting ready to install a tankless water heater, it’s important to gather all the necessary tools and materials, adhere to safety standards, and conduct an initial inspection of the installation area.

Tools and Materials Required

To ensure a smooth installation process, you’ll need:

  • Adjustable wrenches
  • Hot Water Pipe cutters
  • Screwdrivers
  • Tape measure
  • Pipe wrench
  • Soldering tools
  • Teflon tape
  • Venting materials (specific to your model)
  • Matching pipe fittings
  • A carbon monoxide detector (if using a gas tankless water heater)

Ensure that you refer to the installation manual of your tankless water heater for any additional model-specific materials needed.

Safety Precautions

Before beginning the installation, remember to:

  • Turn off the main water supply.
  • Ensure that the power supply or flexible gas supply line is completely turned off.
  • Wear safety glasses and gloves to protect your eyes and hands.
  • Keep a fire extinguisher nearby if you will be soldering pipes.

Initial Inspection

  • Assess the installation area for any existing water or gas leaks.
  • Ensure the location is dry, adequately ventilated, and compliant with local building codes.
  • Measure the space to confirm your new tankless water heater will fit.
  • Check that you have appropriate clearance around the unit for maintenance and ventilation.

Removing the Old Water Heater

Before installing a new tankless water heater, it’s crucial to properly remove your old water heater. This involves ensuring all utilities are turned off, draining the existing tank, and safely disconnecting the unit from your home’s systems.

Shutting Off Utilities

Before starting a tankless water heater install, turn off the power to the water heater. If it’s an electric tankless water heater, switch off the circuit breaker.

For a tankless gas water heater, you’ll want to shut off the gas valve. Then, turn off the water supply to prevent any influx of water during removal.

Draining the Tank

Next, connect a garden hose to the drain valve at the bottom of the tank and run it to a lower area where hot water can be safely disposed of. Open the drain valve and allow the tank to empty, which may take some time depending on the tank’s size.

Disconnecting the Old Heater

Once the tank is drained, disconnect the electricity or gas lines; be cautious with gas lines to prevent leaks. For the water lines, use a pipe wrench to loosen the fittings.

After all connections are safely detached, you can remove the old water heater. Ensure you have assistance as tanks are heavy and awkward to maneuver.

Mounting the Tankless Water Heater

In this section, you’ll learn the crucial steps to properly mount your tankless water heater. From selecting the perfect location to the actual mounting process, the focus is on ensuring a secure and functional installation.

Choosing the Location

When selecting the location for your tankless water heater, think about proximity to gas, electrical, and water lines, as these can impact the ease of installation and operational efficiency.

It’s also essential to consider ventilation requirements and access for maintenance. Look for an area that’s dry and where the unit can be mounted with clearance from combustible materials, as specified by the manufacturer.

Mounting the Unit

After you’ve chosen the appropriate spot, it’s time to mount the unit. Begin by locating the wall studs, as your water heater must be attached securely to these supports.

Depending on your model, you’ll use the mounting bracket or hardware provided. Use a level to ensure the heater is perfectly vertical, which is critical for proper operation.

Drill pilot holes into the studs, affix the mounting hardware, and then secure the heater in place according to the specific instructions provided with your unit. Remember, a firmly mounted tankless water heater leads to a safer and more reliable hot water supply.

Connecting Utilities

Before you get your tankless water heater up and running, it’s essential to correctly connect the utilities. Here’s how you can connect the water line, gas line, and electrical components to ensure your heater operates safely and efficiently.

Water Line Connections

You’ll need to turn off the main water supply before beginning. To connect the water lines to your tankless heater, follow these steps:

  1. Use flexible hoses to connect the cold water line to the inlet and the hot water line to the outlet.
  2. Ensure that all connections are secure and check for any leaks by turning the water on briefly.

For more detail on water line connections, visit Development of an Accurate Feed-Forward Temperature Control Tankless Water Heater.

Gas Line Connections

If your tankless water heater uses gas, proper connection is crucial for safety:

  • Shut off the gas supply before starting.
  • Connect the gas line using a new, flexible gas hose approved for water heaters.
  • Test for leaks using a soap solution on the connections, and look for bubbles that indicate gas is escaping.

Insight on gas connections can be found by studying Impacts of water quality on residential water heating equipment.

Electrical Connections

For electric tankless heaters, you’ll need to:

  • Turn off the circuit breaker related to the water heater.
  • Connect the electrical supply lines to the heater’s junction box.
  • Secure all wiring and ensure that your water heater is properly grounded.

Remember to consult the manufacturer’s instructions for specific wiring requirements. For further technical understanding, read about Electric water heater designs for load shifting and control of bacterial contamination.

Venting the Tankless Water Heater

Proper venting is crucial for the safe and efficient operation of your tankless water heater. Incorrect venting can lead to poor performance and even pose a safety hazard.

Venting Requirements

Your tankless water heater’s ventilation is not just a building code requirement; it’s essential for directing combustion gases outside your home to keep the air quality safe. Be mindful that tankless water heater venting material needs to be specific to the model; usually, category III stainless steel is recommended.

According to the American Council for an Energy-Efficient Economy, the venting must comply with the unit’s specifications. For gas-fired units, it becomes even more critical to use only venting products listed and tested for that particular water heater. Improper venting can lead to dangerous carbon monoxide levels inside your home.

Installing the Vent

When installing the vent for your tankless water heater, first identify the best route from the water heater to the outdoors. The length of the vent and the number of elbows can affect the efficiency and installation of the heater. It’s a best practice to keep the stainless steel vent pipe short and straight.

When assembling the vent, ensure all connections are secure and sealed to prevent exhaust from leaking into your home. The U.S. Department of Energy’s guidelines stress the importance of professional installation, as it requires knowledge of fuel types, local building codes, and proper handling of combustible gases.

Always ensure that the vent installation is in compliance with local building codes and the heater’s manual instructions.

Installing the Water Heater

Before you embark on installing a tankless water heater, it’s critical to ensure that your plumbing and gas or electrical connections align with the new unit’s requirements. Properly securing the unit to a wall or stable surface is also essential for safe operation.

Aligning Connections

Firstly, shut off the water supply. Then, check the manufacturer’s specifications for your tankless water heater to identify the size and type of the connections.

You may need to adjust the existing plumbing to fit the inlet and outlet ports of the new unit. Use flexible hoses for easier alignment and seal all connections with plumber’s tape to prevent leaks.

  • Turn off water supply: Ensure the main water valve is shut off.
  • Measure precisely: Match the water heater connections with your home’s plumbing.
  • Flexible hoses: Utilize these for easy connection and adjustment.
  • Plumber’s tape: Apply to threads to seal connections especially for your hot water faucet.

Securing the Unit

Select a location on a wall or vertical surface where the water heater will be accessible for maintenance and close enough to the existing plumbing and power supply.

The surface should be sturdy to support the weight of the unit. Use the mounting brackets or hardware provided and ensure that the unit is level.

Follow the safety clearances recommended in the manufacturer’s guidelines for proper ventilation and safe operation.

  • Location: Choose an accessible and compliant spot for the heater.
  • Mounting: Use the provided brackets/hardware for installation.
  • Level: Ensure the unit is perfectly horizontal with a level tool.
  • Safety clearances: Respect the manufacturer’s guidelines for space around the heater for safety and ventilation.

Final Steps

Once your tankless water heater is securely mounted, the major components connected, and the necessary safety checks are performed, you’re ready to finalize the installation.

  • Turn On the Gas or Electricity: Depending on your model, you’ll need to supply power. For electric tankless water heaters, restore power at the breaker box. For gas models, turn on the gas valve and ensure it’s free of leaks.
  • Check for Leaks: Apply a water and soap solution to all connections and watch for bubbles, which indicate a gas leak. For water connections, dry them completely, run your system, and look for any water seeping through.
  • Purge Air from Lines: Open the hot water tap on the sink located nearest to your water heater to remove any air trapped in the lines. Let the water run until it flows steadily without any sputtering, indicating air has been purged.
  • Set Temperature: Adjust your heater’s temperature following the manufacturer’s guidelines. A common initial setting is somewhere between 120-125°F (48.9-51.7°C).
  • Finalize Ventilation: For gas heaters, ensure the vent system is adequately sealed as per manufacturer specifications.

Please Note: After you’ve completed all steps, observe your heater for a short while to ensure everything is working correctly and there is no evidence of malfunction.

Remember to register your tankless water heater with the manufacturer to activate the warranty. Save all of your documentation in case you need it for future reference or service.

System Testing and Calibration

Before using your tankless water heater, it’s critical to ensure everything is properly tested and calibrated. This guarantees optimal performance and energy efficiency for your new system.

Checking for Leaks

After installation, verify there are no leaks in the water connections. To do this:

  • Turn on the main water supply and inspect all connections for signs of moisture.
  • Use a solution of soapy water to brush over joints and seals—bubbling indicates a potential leak.

If you detect any leaks, turn off the water supply and tighten the connections or replace the seals as necessary.

Calibrating the Heater

Proper calibration is essential for accurate temperature control and energy efficiency. Follow the steps below:

  • Refer to your heater’s manual to understand the specific calibration process, as this can vary by model.
  • Some heaters may need to be calibrated with the data acquisition system, which often involves adjusting particular settings or allowing a calibration time.

Regular maintenance and calibration checks can improve the longevity of your tankless water heater.

Maintenance Tips

Maintaining your tankless water heater is crucial for efficiency and longevity. Paying attention to regular cleaning and annual inspections can help prevent unexpected breakdowns.

Regular Cleaning

You’ll want to clean the air intake filter regularly to ensure proper airflow. Usually, this is as simple as removing the filter, using a soft brush or a vacuum to remove debris, and then rinsing it under running water.

It’s also important to descale the heat exchanger once a year if you have hard water. This can be done using a vinegar solution to run through the system, effectively removing any calcium buildup that can impact performance.

Annual Inspections

Make it a habit to schedule an annual inspection with a qualified technician. They’ll check for issues like corrosion, proper ventilation, and correct gas pressure.

Ensure that the pressure relief valve is working well to protect against excessive pressure and temperature. An inspection can also involve examining the water flow sensors and checking the in-line screen filter for any blockages.

Regular professional check-ups help ensure that your tankless water heater runs safely and at peak efficiency.

Final Thoughts

When considering the installation of your tankless water heater, remember:

  • Safety first! Always shut off the main water supply and gas/electric connections before beginning.
  • Preparation is key. Assemble the right tools and follow local building codes.
  • Mount securely. Choose a stable location for long-term performance.
  • Connect properly. Ensure water, power, and venting connections are tight and reliable.

Tackling the installation of a tankless water heater can be daunting, but you’ve got this! Your preparation will pay off in energy efficiency and endless hot water.

Review the steps, consult comprehensive guides, and don’t hesitate to seek professional help if needed. Your diligence will ensure a safe and effective setup. Now, get ready to enjoy the benefits of your new tankless water heater!

Frequently Asked Questions

When considering the installation of a tankless water heater, you may encounter a variety of questions. This FAQ section aims to provide clear, concise answers to some of the most common queries.

Can a tankless water heater be installed in a mobile home, and if so, how?

Tankless water heaters can be installed in a mobile home, provided the model is designed for such use and all local codes and regulations are followed. It’s crucial to ensure adequate ventilation and proper gas line sizing when installing in the more compact space of a mobile home.

Are there any incentives or rebates available for installing a tankless water heater, such as through energy efficiency programs or utility companies?

Many governments and utility companies offer incentives or rebates for installing energy-efficient appliances, including tankless water heaters. These can significantly reduce the upfront costs and should be researched beforehand.

Is it necessary to install a water softener or filtration system with a tankless water heater?

While not always necessary, installing a water softener or filtration system with your tankless water heater can prevent scale buildup and extend its lifespan. This is particularly recommended in areas with hard water.

Can a tankless water heater be integrated with existing smart home systems for monitoring and control?

Yes, many modern tankless water heaters are compatible with smart inhome systems. This allows for remote monitoring and control, making it easier to manage energy consumption and ensure hot water availability when needed.


  • Edmund Yeo

    🌱 I'm passionate about sustainable living and renewable energy, and I'm thrilled to share my journey towards a greener, brighter future with you. Join me as I explore the latest innovations, eco-friendly lifestyle tips, and inspiring stories from the forefront of the green energy revolution. Note: This website uses affiliate links which may earn a commission for purchases made at no additional cost to you.

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