View Full Version : Water heater tank fittings

10-26-2008, 03:45 PM
I am getting ready to install a new 40 gallon Bradford/White electric water heater tank. It comes with a combo anode-hot water outlet fitting. Both the cold water inlet and hot water outlet fittings (see photo) are "dielectric waterway fittings with 3/4" NPT tapered male threads." There is a plastic lining inside the nipples, white in the hot water outlet and blue in the cold water inlet. Do I leave these plastic linings in place? The reason I ask is because there is also a black membrane across bottom of the plastic linings that looks like it would block the flow of water. Maybe they keep debris from entering the pipes prior to installation and should be removed? Your thoughts?

10-26-2008, 03:58 PM
Remove them.

They are just there to tell you which is cold and which is hot and to stop anything from dropping in before installation.

10-26-2008, 04:06 PM
I diasagree with krow. The "membrane" is a flapper. These are heat-ckeck nipples. Water will only flow IN on the cold side, and OUT on the hot side. The plastic is the dielectric barrier, to keep water from contacting anypart of the galvanized nipples.

Manufacturers are being constantly "nudged" by uncle sam to up the energy rating, and there is only so much you can do , so they resort to "tricks" like the heat trap to gain a point or two of energy efficiency.

10-26-2008, 04:17 PM
Jimbo has given you the info.. The plastic gives the nipples corrosion resistant properties and that flat is a check valve.

10-27-2008, 10:52 AM
And someday if the heater begins to howl or whine when you use the hot water, you will know where those fittings are so you can remove them.