The Retro-Line Mini is a self-regulating in-pipe heating cable system engineered for small-diameter pipes, including three-quarter-inch and half-inch PEX. In half-inch PEX, there can be a small reduction in flow at the end seal. A method to avoid impedance is to introduce a short three-quarter-inch PEX section where the end seal is housed.

Materials

• Retro-Line Mini self-regulating in-pipe heating cable
• Three-quarter-inch PEX, about 6 inches
• Two John Guest ProLock CTS reducing fittings, 1/2 CTS to 3/4 CTS

Installation Overview

1. Identify the end location that will contain the end seal of the Retro-Line Mini.
2. Install the cable through the half-inch PEX to the designated location.
3. Add a John Guest ProLock CTS reducer on the half-inch PEX. Insert the 6 inch three-quarter-inch PEX section. Add the second reducer back to half-inch PEX.
4. Confirm the end seal is positioned within the three-quarter-inch section and verify all connections are secure.

Safety Notes

• Do not attempt to cut or modify pipe with the heating cable inside.
• Replace the cable if it is damaged or cut.
• Ensure clean, square cuts for proper ProLock engagement.

A conceptual drawing is available on the Retro-Line Mini product page to help visualize the assembly. This approach keeps flow rate intact while delivering reliable freeze protection in smaller diameter PEX lines.