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Step-by-Step Guide: How to Install a Tankless Hot Water Heater

Welcome to our comprehensive guide on how to install a tankless hot water heater. Whether you're looking to upgrade your existing water heater or embark on a DIY installation project, we're here to provide you with the expert advice and step-by-step instructions you need. Installing a tankless hot water heater can be a complex task, but with the right knowledge and tools, it is possible to do it yourself. However, it's important to familiarize yourself with local plumbing and electrical codes before you begin, as they may vary.

In this guide, we will walk you through each stage of the installation process, from upgrading your gas line to mounting the water heater, installing the necessary lines and vents, and finally, turning on the water. We'll also provide you with important tips and considerations to ensure a successful installation.

Key Takeaways:

  • Installing a tankless hot water heater requires familiarity with local plumbing and electrical codes.
  • Upgrading your gas line is often necessary when installing a tankless gas water heater.
  • Properly removing the old water heater is crucial before installing the new tankless unit.
  • Follow the manufacturer's instructions for securely mounting the tankless water heater.
  • Consult professional help for gas line installation and consider hiring a licensed plumber for the entire installation process.

Upgrade Your Gas Line

When installing a tankless water heater, one of the key requirements is upgrading your gas line to ensure it can support the increased demand. Tankless gas water heaters require a sufficient gas line to provide the necessary fuel for their operation. Additionally, they also require adequate combustion air and a vent to remove combustion gas.

In most cases, tankless water heaters require more gas when they fire on compared to traditional tank-style water heaters. This means that your existing gas line may not be able to handle the increased load. It is important to upgrade the gas line and potentially increase the size of the gas pipe from the gas meter to accommodate the higher gas flow.

Upgrading the gas line is a complex task that requires careful planning and adherence to local plumbing codes. It is recommended to hire a licensed contractor who specializes in gas line installation to ensure the work is done correctly and safely. They will have the knowledge and expertise to determine the appropriate gas line size and make any necessary modifications to your existing gas system.

Key Points Details Gas Line Requirements Ensure the gas line is sufficient to provide the necessary fuel for the tankless water heater. Combustion Air and Venting Ensure there is adequate combustion air and a proper vent to remove combustion gas. Increase Gas Line Size Upgrade the gas line and potentially increase the size of the gas pipe from the gas meter to accommodate the higher gas flow. Hire a Licensed Contractor It is recommended to hire a licensed contractor who specializes in gas line installation to ensure the work is done correctly and safely.

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Remove the Old Water Heater

If you are replacing an old water heater tank, the first step is to turn off the water supply and gas supply valves. This will prevent any accidents or leaks while removing the old unit. Next, you need to drain the old water heater by connecting a hose to the drain valve and directing the water to a suitable drain or bucket. Once the tank is empty, disconnect the water lines and gas line using appropriate tools like a wrench or pliers. It's important to follow the manufacturer's instructions or consult a professional if you're unsure.

Once the old water heater is disconnected, it's important to dispose of it properly according to local regulations. This typically involves taking it to a designated recycling center or contacting your local waste management facility for instructions. Improper disposal of old water heaters can have negative environmental consequences, so it's crucial to handle this step responsibly.

Table: Steps to Remove the Old Water Heater

Steps Description Step 1 Turn off the water supply and gas supply valves Step 2 Drain the old water heater Step 3 Disconnect the water lines and gas line Step 4 Dispose of the old water heater properly

By following these steps, you can safely and effectively remove the old water heater and prepare the space for the installation of your new tankless hot water heater.

Mount the Water Heater

Properly mounting the tankless gas water heater is crucial to ensure its stability and safe operation. Follow these tankless water heater installation tips to mount the unit securely:

  1. Choose an appropriate location: Select a wall that provides enough space and meets the manufacturer's clearance requirements. Ensure the wall is structurally sound and can support the weight of the water heater.
  2. Build a mounting box: Construct a sturdy mounting box using 2 x 4 lumber and 3/4-inch plywood. The dimensions of the box should match the specifications provided by the manufacturer.
  3. Attach the mounting box: Position the mounting box on the wall, ensuring it is level and plumb. Secure it using screws or other appropriate fasteners, making sure it is firmly attached.
  4. Mount the water heater: Place the tankless gas water heater inside the mounting box, following the manufacturer's instructions. Use the provided brackets or mounting hardware to firmly secure the unit to the box. Double-check that it is level and stable.

By properly mounting the water heater in a secure location, you can ensure its efficient operation and minimize any potential risks or hazards.

tankless water heater installation

Install the Gas Line

When installing a tankless water heater, one crucial step is to properly install the gas line. It is essential to follow the manufacturer's instructions and adhere to local plumbing codes to ensure a safe and efficient installation. Here are the key steps to install the gas line for your tankless water heater:

  1. Begin by turning off the gas supply at the main shut-off valve. This will prevent any gas leaks while working on the installation.
  2. Next, connect the threaded black iron pipe to the gas shut-off valve. Make sure to use the appropriate pipe size and fittings as specified by the manufacturer.
  3. If necessary, install a tee in the gas line to accommodate additional gas appliances.
  4. Install a sediment trap in the gas line to help prevent debris from reaching the water heater. The sediment trap should be installed as close to the water heater as possible.
  5. Apply a thread sealant designed for gas lines to all connections. This will help ensure a tight and secure fit.
  6. Once the gas line is fully installed, it is crucial to test for gas leaks. Apply a soapy water solution to all connections and look for any bubbles. If bubbles appear, there is a gas leak, and the connection should be tightened or repaired as necessary.

Keep in mind that installing a gas line can be complex and potentially hazardous. If you are not experienced or comfortable working with gas lines, it is highly recommended to hire a licensed professional plumber to ensure a safe and accurate installation.

Table: Materials for Gas Line Installation

Materials Description Threaded black iron pipe Required for connecting the gas shut-off valve to the water heater Pipe fittings Includes elbows, tees, and couplings for connecting the gas line Sediment trap Prevents debris from reaching the water heater Thread sealant Used to ensure a tight and secure connection Soapy water solution Used for testing gas leaks

By following these steps and using the appropriate materials, you can successfully install the gas line for your tankless water heater. Remember, safety should always be a top priority, and if you are unsure or uncomfortable with any aspect of the installation process, it is best to consult a professional plumber.

Install New Water Lines

When installing a tankless water heater, it is crucial to properly connect the water supply lines to ensure a smooth and efficient operation. Follow these helpful tips to install new water lines for your tankless hot water heater:

1. Connect the water supply line

Start by connecting the water supply line to the water heater valves following the manufacturer's instructions. It is important to use the appropriate fittings and connectors to ensure a secure and leak-free connection. Take your time and double-check that all connections are tight and properly sealed.

2. Use copper pipe for hot and cold water lines

For the hot and cold water lines, it is recommended to use copper pipe to connect to the existing water lines. Copper pipe is durable and can withstand high temperatures, making it ideal for a tankless water heater installation. Remember to clean and flux the pipe fittings before soldering them together to ensure a strong bond.

3. Install an expansion tank if necessary

In some cases, depending on your plumbing system and local codes, you may need to install an expansion tank. An expansion tank helps to regulate water pressure and prevent excessive pressure buildup in the water heater. Follow the manufacturer's guidelines and consult with a professional if you are unsure whether an expansion tank is necessary for your installation.

Water Line Installation Tips Use the appropriate fittings and connectors for secure connections Ensures leak-free operation Clean and flux copper pipe fittings before soldering Ensures a strong bond Consider installing an expansion tank if required Regulates water pressure

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Following these tips will help ensure a successful installation of new water lines for your tankless water heater. It is always recommended to consult with a professional plumber if you are unsure or uncomfortable with any aspect of the installation process.

Install the Pressure Relief Valve

One crucial step in the installation of a tankless hot water heater is installing the pressure relief valve. This valve is designed to relieve excess pressure in the system, ensuring the safety of the water heater and your home. Follow these steps to install the pressure relief valve:

  1. Locate the pressure relief valve port on the tankless water heater.
  2. Wrap plumber's tape around the threads of the pressure relief valve.
  3. Insert the pressure relief valve into the port and hand-tighten it.
  4. Use a wrench to tighten the valve until it is snug, taking care not to overtighten.
  5. Attach a discharge pipe to the valve and route it to a suitable location, such as a floor drain or outside.
  6. Secure the discharge pipe using pipe clamps or straps.

Once the pressure relief valve is installed, you can proceed with the rest of the installation process. It is important to follow the manufacturer's instructions for your specific model to ensure proper installation and operation of the pressure relief valve.

Table: Pressure Relief Valve Installation Checklist

Step Description 1 Locate the pressure relief valve port on the tankless water heater. 2 Wrap plumber's tape around the threads of the pressure relief valve. 3 Insert the pressure relief valve into the port and hand-tighten it. 4 Use a wrench to tighten the valve until it is snug, taking care not to overtighten. 5 Attach a discharge pipe to the valve and route it to a suitable location, such as a floor drain or outside. 6 Secure the discharge pipe using pipe clamps or straps.

By properly installing the pressure relief valve, you can ensure the safe and efficient operation of your tankless hot water heater. Remember to follow all manufacturer's instructions and local plumbing codes to maintain compliance and safety.

tankless hot water heater installation

Install the Exhaust Vent

Proper installation of the exhaust vent is crucial for the safe and efficient operation of your tankless gas water heater. The exhaust vent removes combustion gases from the unit and directs them outside. Follow the manufacturer's guidance for venting requirements and choose a location that allows for easy venting.

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When installing the exhaust vent, it's important to use the appropriate materials and ensure a secure connection to prevent gas leaks. Here are some tips to help you with the installation:

Determine the Venting Requirements

Before installing the exhaust vent, determine the specific venting requirements provided by the manufacturer. This will include information on the vent material, diameter, and length restrictions. It's important to follow these guidelines to ensure proper venting and avoid any issues with the unit.

Choose the Right Location

Select a location for the exhaust vent that meets the manufacturer's recommendations. This will typically involve finding a suitable exterior wall or roof space where the vent can be directed outside. Ensure that the location allows for the necessary clearances and does not obstruct any combustible materials.

Install the Vent Pipe

Once you have determined the venting requirements and chosen the location, install the vent pipe according to the manufacturer's instructions. The vent pipe should be the appropriate diameter and made of a suitable material, such as PVC or stainless steel. Use proper fittings and connectors to ensure a secure and tight connection.

Note: Make sure to seal all connections with approved venting sealant to prevent any gas leaks.

By following these tips, you can ensure a proper and safe installation of the exhaust vent for your tankless gas water heater. Remember to always consult the manufacturer's instructions and local building codes for specific guidelines and regulations.

Tankless Hot Water Heater Installation Guide

Now that you have completed the necessary steps to mount the water heater, install the gas line, and connect the water lines, it's time to turn on the water and ensure that your tankless hot water heater is functioning properly. Follow the steps below to complete the installation process.

Step 1: Purge Air from the Water Pipes

Before turning on the water heater, open a faucet to purge any air that may be trapped in the water pipes. Allow the water to flow for a few minutes until you no longer hear any air escaping. Once the water runs smoothly, turn off the faucet.

Step 2: Plug in the Water Heater

Make sure your tankless hot water heater is securely plugged into an electrical outlet. This step will provide power to the unit and allow it to function properly. Ensure that the electrical connection is secure and free from any faults.

Step 3: Insulate the Hot Water Pipe

Insulating the hot water pipe helps to minimize heat loss and ensure that hot water reaches your faucets more efficiently. Use pipe insulation wrap or foam sleeves to cover the exposed section of the hot water pipe. Secure the insulation in place using tape or cable ties.

With these final steps completed, your tankless hot water heater installation is almost finished. Before fully enjoying the benefits of your new water heater, it is important to follow the manufacturer's specific start-up procedures to ensure optimal performance. Check the temperature and outlets to make sure everything is functioning as expected, and make any necessary adjustments according to the manufacturer's instructions.

Step Description 1 Purge air from the water pipes by opening a faucet. 2 Plug in the water heater to provide power. 3 Insulate the hot water pipe to minimize heat loss.

With the completion of these steps, your tankless hot water heater installation is complete. Enjoy the benefits of instant hot water and energy efficiency in your home!

Tankless Water Heater Size: Factors to Consider

When installing a tankless water heater, it's crucial to choose the right size for your specific needs. The size of the water heater will depend on various factors, including the number of bathrooms in your home, the size of your house, and the length of your pipes. By considering these factors, you can ensure that your tankless water heater meets your hot water demands efficiently.

One essential consideration is the number of bathrooms in your home. Each bathroom typically has its own hot water demands, and it's important to choose a tankless water heater that can provide sufficient hot water to meet those needs. Additionally, the size of your house will impact the distance between the water heater and the point of use, which can influence the flow rate and performance of the water heater.

Another factor to consider is the length of your pipes. Longer pipes can lead to increased heat loss and reduced water flow. If you have a large house with long pipe runs, you may need to opt for a larger tankless water heater to compensate for the potential drop in performance.

Table: Tankless Water Heater Sizing Recommendations

Housing Type Number of Bathrooms Suggested Tankless Water Heater Size Apartment or Small House 1 Up to 40 gallons per minute (GPM) Medium House 2-3 Up to 60 GPM Large House 4 or more Up to 80 GPM

It's important to note that these sizing recommendations are general guidelines and may vary depending on specific household usage patterns and preferences. Consult the manufacturer's specifications and guidelines to determine the appropriate size for your tankless water heater.

Consider Hiring a Professional

Installing a tankless hot water heater can be a complex and potentially dangerous task. It is highly recommended to hire a licensed professional plumber to ensure that the installation is done correctly and safely. The cost of professional installation may vary depending on the complexity of the job and any additional requirements.

While DIY installation may seem appealing to save money, it is important to consider the potential risks involved. Improper installation can lead to gas leaks, water damage, and even fire hazards. By hiring a professional, you can have peace of mind knowing that the job will be done right the first time.

A licensed plumber will have the knowledge and experience to navigate local plumbing and electrical codes, ensuring that your tankless hot water heater meets all the necessary requirements. They will also have the right tools and equipment to complete the installation efficiently and safely.

Additionally, hiring a professional can save you time and frustration. A plumber can quickly assess your specific installation needs, recommend the appropriate size and type of tankless hot water heater, and handle any necessary upgrades or modifications to your existing gas line or electrical system.

When considering the cost of professional installation, it is important to factor in the long-term benefits. A properly installed and maintained tankless hot water heater can provide significant energy savings over time. It can also improve the overall comfort and convenience of your home, providing a constant supply of hot water on demand.

In conclusion, while it may be tempting to attempt a DIY installation, it is highly recommended to hire a licensed professional plumber for the installation of a tankless hot water heater. The cost of professional installation is worth the peace of mind, safety, and long-term benefits that come with a properly installed system. Consult with a trusted plumber to ensure a successful and hassle-free installation process.

Tips for Successful Tankless Water Heater Installation

When it comes to installing a tankless water heater, following the right tips can make the process smoother and more successful. Here are some important recommendations to keep in mind:

Gather the necessary tools and materials

Before you start the installation, make sure you have all the tools and materials required. This includes a pipe wrench, drill/driver, keyhole saw, hand truck (if replacing a water heater), and any specific components recommended by the manufacturer. Having everything on hand will save you time and prevent unnecessary delays.

Follow the manufacturer's instructions

Each tankless water heater model may have specific installation instructions provided by the manufacturer. It is crucial to follow these instructions carefully to ensure proper installation and avoid any potential issues. Failure to comply with the manufacturer's guidelines could result in damage to the unit or compromise its performance.

Test for leaks before turning on the water heater

Prior to turning on the water heater, it is essential to test for any leaks in the gas and water lines. Perform a thorough check to ensure all connections are secure and free from leaks. This step is crucial for safety and to prevent any damage to your property. If you detect any leaks, address them immediately before proceeding.

By adhering to these tips, you can increase the likelihood of a successful tankless water heater installation. Remember to prioritize safety, follow the manufacturer's instructions, and test for leaks to ensure optimal performance.

Conclusion

Installing a tankless hot water heater can be a challenging task, but with the right knowledge and preparation, it is possible to do it yourself. However, it is highly recommended to hire a licensed professional plumber if you are not experienced or comfortable with plumbing and electrical work. Safety should always be a top priority when working with gas and electrical systems.

By following this tankless hot water heater installation guide, you can ensure a successful installation process. Remember to familiarize yourself with local codes, gather all the necessary tools and materials, and carefully follow the manufacturer's instructions. Testing for gas and water leaks before turning on the water heater is crucial for safety.

Consider the size of the tankless water heater based on your needs and consult the manufacturer's specifications for guidance. If in doubt, it is always a good idea to consult a professional to determine the appropriate size and ensure optimal performance.

Whether you choose to install a tankless hot water heater yourself or hire a professional, the benefits of having an efficient and on-demand hot water system are worth the effort. Enjoy the convenience and energy savings of a tankless hot water heater in your home!

FAQ

What tools do I need to install a tankless hot water heater?

You will need a pipe wrench, drill/driver, keyhole saw, and a hand truck if you are replacing a water heater with a tank.

Do I need to upgrade my gas line for a tankless hot water heater?

In most cases, yes. Tankless gas water heaters require more gas when they fire on compared to tank-style water heaters, so you may need to upgrade your gas line and potentially increase the size of the gas pipe from the gas meter. It is recommended to hire a licensed contractor for this task.

How do I remove an old water heater?

To remove an old water heater, start by turning off the water supply and gas supply valves. Drain the old water heater and disconnect the water lines and gas line. Dispose of the old water heater properly, following local regulations.

How do I mount a tankless hot water heater?

Tankless gas water heaters need to be securely mounted on a wall using a mounting box made of 2 x 4 lumber and 3/4-inch plywood. The mounting box should be sturdy enough to support the weight of the unit. Follow the manufacturer's instructions for the proper clearances and venting requirements.

How do I install the gas line for a tankless hot water heater?

If you are familiar with gas pipe connections, you can continue the gas line to the new water heater using threaded black iron pipe. Install a gas shut-off valve, tee, and sediment trap following the manufacturer's instructions. Use thread sealant designed for gas lines and test the gas line for leaks before turning on the gas. It is recommended to hire a licensed contractor for gas line installation.

How do I connect the water supply lines for a tankless hot water heater?

Connect the water supply line to the water heater valves following the manufacturer's instructions. Use copper pipe to connect the hot and cold water lines to the existing water lines. Make sure to clean and flux the pipe fittings before soldering them together. If necessary, install an expansion tank. Use bell hangers to secure the pipe against the wall.

How do I install a pressure relief valve for a tankless hot water heater?

Install a pressure relief valve according to the manufacturer's instructions. This valve helps relieve pressure if it builds up in the water heater. It is an important safety feature. Make sure to follow the manufacturer's guidelines for installation.

How do I install the exhaust vent for a tankless hot water heater?

Tankless gas water heaters require a direct-vent exhaust system, which is typically piped directly to the outside. Follow the manufacturer's guidance for venting requirements and choose a location that allows for easy venting. Install the vent pipe using the appropriate materials and secure it to the wall. Make sure to seal all connections to prevent gas leaks.

What do I do after installing the tankless hot water heater?

After installing the tankless hot water heater, open a faucet to purge air from the water pipes and turn it off. Plug in the water heater and insulate the hot water pipe. Turn on the gas and follow the manufacturer's start-up procedures. It is important to check the temperature and outlets to ensure the water heater is functioning properly.

How do I determine the appropriate size of a tankless water heater?

The size of the tankless water heater you need will depend on factors such as the number of bathrooms, the size of your home, and the length of your pipes. Consider the amount of hot water you need at any given time and consult the manufacturer's specifications to determine the appropriate size.

Should I hire a professional for tankless water heater installation?

Installing a tankless hot water heater can be a complex and potentially dangerous task. It is highly recommended to hire a licensed professional plumber to ensure that the installation is done correctly and safely. The cost of professional installation may vary depending on the complexity of the job and any additional requirements.

What are some tips for a successful tankless water heater installation?

Some tips for a successful tankless water heater installation include familiarizing yourself with local plumbing and electrical codes, following the manufacturer's instructions carefully, testing for gas and water leaks before turning on the water heater, considering installing an expansion tank if required, insulating hot water pipes to minimize heat loss, and regularly maintaining and cleaning the water heater to ensure optimal performance.

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