Tubing Installation

tubing install diagram

Step 1: Clean the Panels

Clearing the panels and tubing channels of debris will ensure the tubing sits flush and level. This is essential to a well functioning radiant system.

  • Use a broom, shop vacuum or leaf blower to clear the debris from the panel and tubing channels
  • Use a 1/2″ conduit to break loose stuck-on material

Step 2: Mark the Tubing Paths

  • Follow the Tubing Layout plan set and mark the tubing paths on your panels with a permanent marker
  • Clearly mark turns, bury points, custom routes, and manifold locations
  • Mark locations of all plumbing waste lines
  • Mark each loop to avoid any future confusion
  • Use a Sharpie or wax pencil to mark panels.
  • Use a 3/4″ drill bit to create a 3/4″ x 11/2″ bury point which will help prevent the tube from kinking.

Step 3: Return Lines to Manifolds

To return the PEX tubing back to the manifolds, there are a few different options which will work.

  • Method 1
    Use the existing channels in the panels to return the tubing to the manifold
  • Method 2
    Create custom routes in the panel and return the tubing back to the manifold
  • Method 3
    Create a bury point and feed the tubing back to the manifold by going through the subfloor (illustration)
  • Method 4
    Use the “panel cut back” to create a tubing channel above the slab for the tubing to return to the manifold. Fill with Portland cement to create a level surface (illustration)

Step 4: Custom Routes

Follow the instructions for Custom Routes
custom routing a panel


Step 5: Install Tubing

  • Avoid installing tubing at temperatures below 50˚F as the tubing becomes rigid and difficult to bend
  • ONLY use tubing from our Approved Tubing List
  • Use a 16oz. rubber mallet to secure the tubing in the channel (be sure the tubing sits level and flush with the top of the panel)
  • DO NOT use silicone/adhesive in the channels
  • Tape over the ends of the tubing to prevent debris from clogging the lines
  • A tubing uncoiler will help avoid twists and kinks when installing the tubing. It is an excellent investment and highly recommended for large jobs
  • Use nail plates to secure tubing as needed and remove before finish floors are installed

Step 6: Install Manifold(s)

  • Follow all installation details and specifications documented by the manufacturer. Manifolds are usually placed in closets or between interior wall stud bays with an access door
  • Clearly mark all supply and return loops. Document rooms and zones on the manifolds to avoid future confusion
  • Pressure test all loops to the mechanical code requirement of 100 PSI for 15 minutes. After this, the PSI will drop 5-10% (this is normal)
  • After the 15 minutes, lower the air pressure to 60 PSI and maintain during the construction process.
  • After this, the PSI will drop 5-10% (this is normal)
See Manifold Install guide.

Minimum Framing Dimensions:
Minimum Framing Dimensions

Step 7: Tubing Repair

Every tubing manufacturer makes a repair coupler to repair a punctured section of tubing.

Repairing tubing damage is an easy fix and should require less than 30 minutes to complete.

  • Pop the tube out of the tubing channel
  • Cut out the damaged area and insert the coupler
  • Chisel a groove into the panel to accommodate the size of the coupler
Other recommendations:
  • The tubing MUST be level and flush with the surface of Warmboard.
  • Consider Ram Board (or equivalent) to help protect the tubing in high traffic areas.

Manifold cabinet diagram

manifold cabinet