Can I Use Pex For Water Heater: Find Out Quickly!

Are you planning a plumbing project involving the PEX pipe and your water heater? You might be curious about the safety of such a task. This post will guide you through an understanding of PEX tubing, important constraints under the Uniform Plumbing Code (UPC), and best practices to ensure the safe connection of PEX pipe to your water heater.

Hang tight! We’re here to clear all doubts on this subject in a thorough yet straightforward manner.

Key Takeaways

  • The Uniform Plumbing Code (UPC) requires an 18-inch separation between PEX pipe and water heaters to prevent expansion issues.
  • To connect PEX to a water heater, it is recommended to extend a copper or stainless steel intermediate pipe before connecting the PEX tubing.
  • PEX tubing offers benefits such as flexibility, durability, and thermal resistance when connecting to electric water heaters.
  • Proper installation techniques, adherence to local codes, and manufacturer’s instructions are crucial for a safe and effective connection of PEX pipe to a water heater.

Can PEX Pipe be Connected to a Water Heater?

The compatibility of PEX pipes with water heaters is determined by the Uniform Plumbing Code (UPC 604.13) and the specific guidelines provided by manufacturers.

Understanding the Uniform Plumbing Code (UPC 604.13)

The Uniform Plumbing Code (UPC 604.13) is a specific set of regulations that dictate how PEX tubing should be used in any given plumbing setup, including the connection to water heaters. According to this code, one must maintain an 18-inch separation between the PEX piping and any heat source such as a water heater.

The reasoning behind these guidelines lies in the composition of PEX which, being made from polyethylene, can expand under excessive heat exposure.

In order to conform with UPC’s rules, it is suggested to extend an intermediate pipe at least 18 inches away from the water heater before making any connection using PEX. This typically involves connecting copper pipes or stainless steel corrugated flex first to the heater and then extending them outwards by the required distance before finally connecting your PEX line.

Ensuring adherence to these safety measures not only abides by local codes but also effectively prevents expansion issues associated with direct exposure of PEX tubing to high heating temperatures—thus significantly enhancing overall system functionality and lifespan.

Exploring the compatibility of PEX with water heaters

PEX tubing is a popular choice for plumbing systems due to its flexibility and durability. When it comes to connecting a PEX pipe to a water heater, it’s important to understand the compatibility between the two.

According to the Uniform Plumbing Code (UPC), PEX tubing should not be installed within 18 inches of a water heater. This is because PEX pipes are made from polyethylene and can expand under excessive heat.

To connect PEX to a water heater, it is recommended to extend a pipe 18 inches from the water heater and then connect the PEX tubing to that pipe. This serves as an intermediate connection, ensuring that both materials are compatible and reducing any risks of damage or leaks.

It’s worth noting that alternatives such as copper pipes or stainless steel corrugated flex can also be used for water heater connections if you prefer not to use PEX tubing.

Considerations for Connecting PEX to Electric Water Heaters

When connecting PEX to electric water heaters, it is important to consider the benefits of using PEX tubing for these connections and ensure proper installation and system compatibility.

Benefits of using PEX for electric water heater connections

PEX tubing offers several benefits when it comes to connecting it to electric water heaters. Firstly, PEX is highly flexible and can be easily maneuvered around obstacles, making installation much simpler for novice homeowners.

Additionally, PEX is corrosion-resistant, meaning it won’t degrade over time like copper piping can. This makes it a durable and long-lasting option for your water heater connections.

Furthermore, PEX handles hot water exceptionally well and is thermally resistant, ensuring that the high temperatures of the water in your electric water heater won’t cause any damage or compromise its integrity.

You can have peace of mind knowing that your PEX connections are capable of handling the heat without any issues.

Lastly, using PEX for electric water heater connections eliminates the need for soldering or other complex plumbing techniques required with traditional copper pipes. With PEX fittings specifically designed for hot water applications and simple push-fit connectors available in most home improvement stores, connecting your electric water heater becomes a breeze.

Overall, choosing to use PEX tubing for connecting your electric water heater brings ease of installation, durability against corrosion, thermal resistance against high temperatures,

Ensuring proper installation and system compatibility

To ensure a safe and effective installation when connecting a PEX pipe to a water heater, there are a few important considerations to keep in mind:

  1. Follow local codes: Before starting any plumbing project, it is essential to check the local plumbing codes and regulations. This will ensure that the installation meets the required standards for safety and functionality.
  2. Manufacturer’s instructions: Always consult the manufacturer’s instructions for both the PEX tubing and the water heater. These instructions will provide specific guidelines on how to properly connect the PEX pipe to the particular model of water heater you are working with.
  3. Choose suitable fittings: Selecting the right fittings is crucial for a secure connection between the PEX pipe and the water heater. Use fittings that are specifically designed for use with PEX tubing, ensuring compatibility with both materials.
  4. Use proper tools: Using the correct tools for cutting, crimping, or expanding PEX tubing is important for achieving a professional installation. This will ensure leak-free connections and minimize potential issues down the line.
  5. Consider expansion and contraction: PEX tubing can expand and contract due to temperature changes. When connecting PEX to a water heater, leave some space for this movement by using flexible connectors or allowing sufficient slack in the pipe.
  6. Insulate exposed pipes: If any part of your connection is exposed or runs through an unconditioned space (such as an attic or crawl space), consider insulating it to protect against freezing temperatures and heat loss.
  7. Conduct pressure tests: After completing the installation, it is recommended to perform pressure tests to check for any leaks before putting your system into full operation. This will help identify any potential issues early on and avoid costly repairs or damage.

Connecting PEX to Water Heaters: Best Practices

To ensure a safe and effective connection, it is recommended to extend a pipe from the water heater before connecting PEX tubing.

Extending a pipe from the water heater before connecting PEX

When connecting PEX tubing to a water heater, it is recommended to extend a pipe from the water heater before connecting the PEX. This helps to ensure proper installation and system compatibility. Here are some important considerations:

  1. Use an intermediate pipe: PEX cannot be directly connected to a water heater without using an intermediate pipe. The intermediate pipe acts as a transition between the water heater and the PEX tubing.
  2. Length of the pipe: It is recommended to extend the pipe 18 inches from the water heater before connecting the PEX. This distance helps to reduce potential damage caused by excessive heat and expansion of the PEX tubing.
  3. Material of the intermediate pipe: Copper pipes or stainless steel corrugated flex are commonly used as intermediate pipes when connecting PEX tubing to a water heater. These materials have good heat resistance and durability.
  4. Proper connection techniques: When connecting the PEX tubing to the extended pipe, it is important to use suitable connectors and follow the manufacturer’s instructions for proper installation. This ensures a secure and leak-free connection.
  5. Compliance with local codes: Always consult local plumbing codes and regulations when installing or modifying plumbing connections, including those involving PEX tubing and water heaters. Following these codes helps ensure safety and compliance.

When connecting PEX to water heaters, it is important to follow recommended techniques to ensure a safe and efficient installation. Here are some guidelines to keep in mind:

  1. Use proper PEX fittings: When connecting PEX tubing to a water heater, it is essential to use fittings specifically designed for PEX pipes. These fittings provide a secure connection and prevent leaks.
  2. Size the PEX correctly: Choose the appropriate size of PEX tubing for your specific hot water needs. The size should be based on factors such as flow rate and pressure requirements.
  3. Install an intermediate pipe: To connect PEX tubing to a water heater, it is recommended to extend a pipe from the water heater first. This provides a stable base for connecting the PEX tubing and helps prevent stress on the connections.
  4. Use appropriate tools for installation: Utilize specialized tools such as crimpers or cinch clamps for securing the PEX fittings onto the tubing. These tools ensure proper compression and create reliable connections.
  5. Follow manufacturer’s instructions: Always refer to the manufacturer’s instructions when installing PEX tubing with a water heater. Each brand may have specific recommendations that need to be followed for optimal performance and longevity.
  6. Inspect for leaks: After completing the installation, thoroughly check all connections for any signs of leaks or drips. Address any issues immediately to prevent potential water damage or loss of efficiency.

Frequently Asked Questions

1. Can PEX pipe be safely connected to a water heater?

Yes, PEX pipes can be safely connected to a water heater. It is a common and approved method for plumbing installations.

2. What are the advantages of using a PEX pipe for connecting to a water heater?

PEX pipe is flexible, corrosion-resistant, and has excellent resistance to heat and cold. It is also easy to install and requires fewer fittings compared to traditional copper or PVC pipes.

3. Are there any specific considerations when connecting a PEX pipe to a water heater?

When connecting a PEX pipe to a water heater, it is important to use appropriate fittings that are compatible with both the PEX material and the type of connection required by the water heater manufacturer. Following proper installation techniques and codes is crucial for safety.

4. Can I install PEX piping myself or should I hire a professional for this job?

While installing PEX piping can be done as a DIY project, it may be best to hire a professional plumber who has experience working with PEX materials and understands local plumbing codes. This ensures that the installation is done correctly and meets all safety requirements.


In conclusion, connecting a PEX pipe to a water heater can be safe and effective when done following the proper guidelines. It is important to adhere to local codes and manufacturer’s instructions to ensure a secure installation.

By utilizing best practices, such as extending a pipe before connecting the PEX, homeowners can enjoy the benefits of using this durable and thermally resistant material for their water heater connections.