Material Performance Differences
PEX works for both applications. Hot water increases expansion. Cold water minimizes expansion. Pressure ratings differ by temperature. All PEX types handle both. Installation methods are identical.
Color Coding Standards
Red PEX indicates hot water lines. Blue PEX marks cold water lines. White or gray is multi-purpose. Consistent coding avoids confusion. It helps with future repairs. Follow this standard practice.
Expansion and Contraction Management
Hot water causes PEX to expand. Allow slack in long runs. Use expansion loops if needed. Cold lines need less slack. Plan routing accordingly. Avoid tight fittings.
Pressure Rating Variations
PEX has lower pressure rating for hot water. Example: 160 psi at 73°F. Rating drops to 100 psi at 180°F. Cold water maintains full rating. Check manufacturer charts. Never exceed ratings.
Insulation Requirements
Insulate all hot water lines. This saves energy. It delivers hotter water faster. Cold lines may need insulation too. It prevents condensation in humid areas. Use appropriate insulation thickness.
