How To Install PEX Tubing For Baseboard Heat

Installing a baseboard heating system can significantly improve the comfort and warmth of your home. PEX (cross-linked polyethylene) tubing has become a popular choice for distributing hot water in radiant heating systems due to its flexibility, durability, and ease of installation. In this guide, we will walk you through the steps of installing PEX tubing for a baseboard heating system, ensuring efficient and effective heat distribution throughout your space.

Things You Need to Know Before Installing PEX Tubing For Baseboard Heat

  • PEX tubing can be installed in long runs without the need for additional fittings.
  • PEX tubing can expand up to three times its diameter when exposed to freezing temperatures.
  • PEX tubing can be installed using a manifold system, which allows for individual control of each heating zone.

Materials and Tools You’ll Need

Before you begin the installation process, it’s essential to gather all the necessary materials and tools to ensure a smooth and successful project. Here’s a list of what you’ll need:


  • PEX tubing (compatible with hot water)
  • Baseboard heating units
  • Insulation (if required by local building codes)
  • PEX fittings (elbows, tees, couplings, adapters)
  • PEX crimp or clamp rings
  • PEX manifold (optional, for more complex systems)
  • Insulated PEX tubing (for outdoor or exposed installations)
  • Pressure-treated wood blocking (for attaching baseboard units)


  • Measuring tape
  • Pipe cutter or PEX tubing cutter
  • Crimping tool or clamp tool
  • PEX expansion tool (for expansion fittings)
  • Drill and appropriate bits
  • Screwdriver
  • Level
  • Pencil or marker
  • Channel locks or adjustable wrench
  • Safety equipment (gloves, safety glasses)

Step-by-Step Installation Guide

1. Planning and Preparation

Before you start installing PEX tubing, it’s crucial to plan out the layout of your baseboard heating system. Determine where the supply and return lines will run and how many baseboard units you’ll be installing. Ensure that you have an adequate heat source, such as a boiler or water heater, and that your system is designed to accommodate the added load.

2. Marking and Mounting

  • Use a pencil and level to mark the height at which you’ll mount the baseboard units on the walls. Make sure they are consistent throughout the installation.
  • If needed, install pressure-treated wood blocking between wall studs to provide a sturdy surface for attaching the baseboard units.

3. Cutting and Fitting PEX Tubing

  • Measure and cut the PEX tubing to the appropriate lengths for each section of the baseboard loop. Add a few extra inches to each end to allow for expansion and contraction.
  • Attach PEX fittings, such as elbows and tees, to create the desired layout for the tubing. Be sure to follow the manufacturer’s guidelines for proper fitting installation.
  • If using expansion fittings, expand the PEX tubing using a PEX expansion tool and insert the fittings securely.

4. Installing Baseboard Units

  • Attach the baseboard heating units to the wood blocking using screws or other appropriate fasteners. Make sure they are level and securely in place.
  • Slide the PEX tubing into the designated channels on the back of the baseboard units, ensuring a snug fit.

5. Connecting PEX Tubing

  • Begin by connecting one end of the PEX tubing to the supply line coming from your heat source. Use PEX crimp or clamp rings to secure the connection. Follow the manufacturer’s instructions for proper crimping or clamping techniques.
  • Run the PEX tubing along the marked path, securing it to the wall using appropriate clips or hangers. Maintain proper clearances from electrical wiring and other utilities.
  • When you reach the last baseboard unit, connect the PEX tubing to the return line. Again, ensure a secure connection using crimp or clamp rings.

6. Pressure Testing

  • Before covering the PEX tubing with the baseboard units, it’s essential to pressure test the system for any leaks. Close all the valves and use a pressure testing gauge to pressurize the system to the recommended pressure (usually around 100 psi). Monitor the gauge for any pressure drops over a certain period.

7. Insulation (if required)

  • Depending on local building codes and climate conditions, you may need to insulate the PEX tubing to prevent heat loss and ensure optimal system efficiency. Use appropriate insulation materials and methods for your specific installation.

8. Finishing Touches

  • Once you’ve confirmed that the system is leak-free and functioning correctly, cover the PEX tubing with the baseboard units.
  • Bleed any air trapped in the system by opening the air bleed valves on each baseboard unit.
  • Set the thermostat to the desired temperature and let the system run to ensure even heat distribution.

Additional Tips and Considerations

– Sizing the PEX Tubing

  • It’s crucial to select the right size of PEX tubing based on the heating load and the length of the tubing runs. Undersized tubing may result in inadequate heat distribution, while oversized tubing can lead to inefficiencies.

– Expansion and Contraction

  • PEX tubing expands and contracts with temperature changes. Allow for sufficient expansion gaps and use bend supports to prevent kinks and stress on the tubing.

– Manifold Systems

  • In larger installations, using a PEX manifold can simplify the distribution of hot water to different zones, improving control and efficiency.

– Consult Local Codes

  • Always check and adhere to local building codes and regulations when installing PEX tubing for baseboard heating. Obtain any necessary permits and inspections.

– Professional Assistance

  • If you’re unsure about any aspect of the installation process, it’s advisable to seek the assistance of a professional plumber or heating contractor to ensure a safe and effective installation.

Safety Considerations for DIY PEX Tubing Installation

When embarking on a DIY PEX tubing installation project, it’s essential to prioritize safety to ensure the well-being of yourself, your family, and your property. While PEX tubing is known for its ease of use and versatility, following proper safety practices can help prevent accidents and ensure a successful and trouble-free installation. Here are some critical safety considerations to keep in mind:

1. Protective Gear and Clothing

Before you begin working with PEX tubing and associated tools, ensure you are wearing appropriate protective gear, including:

  • Safety Glasses: Protect your eyes from debris, dust, and any potential splashes.
  • Gloves: Wear gloves to shield your hands from sharp edges, hot surfaces, and potential cuts or abrasions.
  • Work Clothing: Choose clothing that covers your body to minimize exposure to hot or sharp materials.

2. Tool Safety

Using the right tools for the job and handling them properly is crucial for your safety. Follow these guidelines:

  • Proper Use: Use tools according to their intended purpose and manufacturer instructions.
  • Tool Maintenance: Keep your tools well-maintained and in good working condition to prevent accidents.
  • Tool Storage: Store tools in a safe and organized manner to prevent tripping hazards and damage.

3. Hot Water and Steam Hazards

PEX tubing installations often involve working with hot water and steam. To avoid burns and scalds:

  • Heat-Resistant Gloves: Wear heat-resistant gloves when working with hot PEX tubing or heated water.
  • Heat Sources: Be cautious around heat sources such as boilers, water heaters, and soldering equipment.

4. Fire Prevention

While PEX tubing itself is not flammable, certain installation processes may involve open flames (e.g., soldering copper fittings). To prevent fires:

  • Fire Extinguisher: Keep a fire extinguisher within easy reach and know how to use it.
  • Fire-Safe Area: Perform soldering or other open-flame work in a well-ventilated area away from flammable materials.

5. Sharp Objects

Cutting PEX tubing and handling fittings can expose you to sharp edges. Take precautions to avoid cuts:

  • Pipe Cutters: Use pipe cutters or PEX tubing cutters to make clean, controlled cuts.
  • Handling Fittings: Be careful when handling PEX fittings to avoid cuts or punctures.

6. Electrical Safety

If your installation involves electrical components (e.g., circulator pumps), follow electrical safety guidelines:

  • Power Off: Turn off power to relevant circuits before working on electrical components.
  • Grounding: Ensure proper grounding to prevent electric shock.

7. Ventilation

When working indoors or in enclosed spaces, ensure adequate ventilation to prevent the buildup of harmful fumes or gases:

  • Exhaust Fans: Use exhaust fans or open windows to promote fresh air circulation.

8. Pressure Testing Safety

Before pressurizing the PEX tubing system for leak testing, consider the following:

  • Proper Pressure: Use a pressure gauge to monitor and maintain safe testing pressure levels.
  • Protective Gear: Wear eye protection and gloves while conducting pressure tests.

9. Consult Professionals

If you encounter complex issues or are unsure about any aspect of the installation, seek advice or assistance from qualified professionals, such as plumbers or heating contractors.

10. Local Building Codes

Adhere to local building codes and regulations throughout your PEX tubing installation to ensure compliance with safety standards.

Remember, safety should always be your top priority when working on any DIY project. By following these safety considerations, you can minimize risks and enjoy a successful and secure PEX tubing installation that provides efficient and reliable plumbing or heating solutions for your home.

How to Troubleshoot Common PEX Tubing Installation Issues

PEX tubing installations can sometimes encounter issues that require troubleshooting and corrective action. In this guide, we’ll explore some common PEX tubing installation issues and provide practical solutions to help you address these challenges effectively.

1. Uneven or Inadequate Heat Distribution

Possible Causes:

  • Improper Layout: If the PEX tubing layout is not well-planned, certain areas of the space may receive inadequate heat, resulting in cold spots.
  • Flow Imbalance: Unequal flow rates in the PEX tubing loops can lead to uneven heat distribution, where some baseboards or radiators are hotter than others.

Troubleshooting and Solutions:

  • Reevaluate Layout: Review the layout of the PEX tubing and ensure it provides even coverage across the heated space. Adjust the tubing length and layout if necessary.
  • Hydronic Balancing: If you have a multi-zone system, consider hydronic balancing. Adjust flow rates using flow control valves or zone valves to ensure each zone receives the appropriate amount of heat.

2. Noisy PEX Tubing System

Possible Causes:

  • Water Hammer: Rapidly closing or opening valves can create water hammer, leading to loud knocking or banging noises in the PEX tubing.
  • Air in the System: Air trapped in the PEX tubing can cause gurgling or bubbling sounds as water flows through.

Troubleshooting and Solutions:

  • Install Water Hammer Arrestors: Water hammer can be reduced by installing water hammer arrestors near quick-closing valves.
  • Purge Air from the System: Bleed air from the PEX tubing system using air bleed valves on baseboard units or radiators. Properly bleeding the system can help eliminate gurgling sounds.

3. PEX Tubing Leaks

Possible Causes:

  • Poor Crimp or Clamp Connections: Inadequate crimping or clamping of PEX fittings can lead to leaks at connection points.
  • Damage during Installation: Accidental damage to PEX tubing or fittings during installation can result in leaks.

Troubleshooting and Solutions:

  • Inspect Connections: Thoroughly inspect all crimp or clamp connections for proper installation. Make sure the crimp rings are evenly and fully compressed around the PEX and fittings.
  • Replace Damaged Sections: If you identify any damaged PEX tubing sections, cut out the damaged area and replace it with a new section. Use proper crimping or clamping techniques for the new connection.

4. Inadequate Water Pressure or Flow

Possible Causes:

  • Undersized PEX Tubing: Using PEX tubing with insufficient diameter for the heating load can result in reduced water flow and pressure.
  • Blockages: Debris or sediment in the PEX tubing can obstruct water flow, leading to inadequate heat distribution.

Troubleshooting and Solutions:

  • Check PEX Sizing: Ensure that the PEX tubing diameter is appropriate for the system’s flow requirements. Consider consulting with a professional if you’re unsure about sizing.
  • Flush the System: If you suspect blockages, flush the PEX tubing system to remove debris and sediment. Install appropriate filters to prevent future blockages.

5. Freezing PEX Tubing

Possible Causes:

  • Inadequate Insulation: Insufficient insulation around PEX tubing in cold areas can lead to freezing and potential damage.

Troubleshooting and Solutions:

  • Add Insulation: Ensure that PEX tubing in cold or exposed areas is adequately insulated to prevent freezing. Use insulation materials designed for PEX tubing


Installing PEX tubing for a baseboard heating system can be a rewarding DIY project that enhances the comfort of your home. By following these step-by-step guidelines and considering the tips provided, you’ll be well-equipped to create an efficient and reliable heating system that keeps your space warm and cozy throughout the colder months. Remember, proper planning, careful execution, and attention to detail are the keys to a successful PEX tubing installation for baseboard heat.

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