[LazyPup]

You inspector is correct. PVC pipe may be used for "SUPPLY PIPING" (water line from the source to the structure) but MAY NOT be used for any "Distribution piping" (water piping within the structure.)

There are a number of code important code points in regards to water heater T&P relief valves:

Temperature and Pressure Relief Valve drain piping per the International Residential Code (IRC) and the Uniform Plumbing Code(UPC).


REF: IRC 2803.6.1 & UPC-608.5

1. The T&P drain must terminate outside the structure, or inside the structure into an approved indirect waste receptor. (In an unfinished basement that has a floor drain the T&P may terminate on the floor.

2. The IRC requires the point of discharge to be within 6" of the receptor or finished grade when outside.

3. The UPC requires the point of discharge to be within 6" to 24" above the receptor or finished grade when discharged outside.

4. The drain line diameter MUST BE equal to or greater than the T&P dischrge port outlet.

5.The drain line Must be pitched in the direction of the discharge port. May not run uphill, may not be trapped and may not have any restrictions to flow.

6.There may be no kinks or restrictions to flow.

7. The discharge end of the pipe MUST BE visible.

8.There shall be no shutoff valves and the discharge end of the pipe may not be threaded.

9. Must be plumbed with the same materials as approved for "Water Distribution" I.E. Galvanized Iron pipe, Hard drawn Copper Pipe or CPVC (Local codes may not permit CPVC)

10 TPRV may not discharge into the water heater drip pan.