I have read that National Code requires you to use copper for 18 inches from your water heater. How can I do this when everything existing is PEX?
I need to replace my existing low boy water heater next to my kitchen sink. It was installed by the builder ten years ago. All the pipe in the house is PEX. The existing water heater is connected using PEX as well.
The supply line comes directly thru the wall to the HW Heater. There is no space to run 18 inches of copper! The heater is under the kitchen counter, and the countertop is directly over it. Only about an inch clearance.
Best Answer
Although copper may not be required, it is possible that PEX is prohibited.
One reason for this would be building codes / regulations. For instance, the UPC states:
The specifics of what your local regulations state can vary widely, so you should inquire with your local officials.
Another potential restriction could come from piping manufacturer's rules or recommendations. For example:
from the TUBING INSTALLATION PRACTICES section of INSTALLATION HANDBOOK: Cross-linked Polyethylene (PEX) Hot and Cold Water-Distribution Systems of the Plastic Pipe and Fittings Association.