Ask Arnie, by CAPHCC Code Chairman Arnie Rodio Code Information, News for PHCC Members - All

  1. Regarding proper installation of a drip leg or sediment trap on a water heater or gas appliance:
    1. Is this installed before the flex or after?
    2. Is this required by code or optional?

This has been kicked around a lot.  The code under section 1210.8.1  just requires that you have a drip where condensate may collect in other than dry gas conditions.   Section 1210.8.2  gives locations as to be readily assessable (for servicing)  and they cannot be located where they can freeze.   A sediment trap under Section 1211.8 is required to be downstream of the appliance shut off valve and as close as practice to the inlet of the appliance. 

The question arises as to if the connector is part of the inlet of part of the piping. To play it safe come out of the water heater with a nipple, install the sediment trap, then go with the flex back to the valve that would be on the gas stub.

  1. In concealed spaces on gas piping is a right/left nipple required or union?

Section 1210.3.1 requires the use of a left and right.  A union can only be used in an exposed space or with access.


Arnie Rodio is the owner of Pace Setter Plumbing and is a 3rd generation plumber.  A member of PHCC since 1990, Rodio is a PHCC of California Past President, a PHCC GLAA Past President, and serves on the Technical Committee for IAPMO, which is responsible for the Uniform Plumbing Code.