I installed a Bradford White electric water heater this past weekend
and everything went well, except the threaded connections on the top of
the water heater are leaking. The adaptor used to connect to the CPVC
piping was a 3/4" Brass Female Adaptor (threaded brass on the bottom,
female cpvc on top). I wrapped the connectors coming out of the heater
with Teflon Tape (3-4 times around) and tightened the adaptor onto the
connection, but it is still leaking (very slowly, but still leaking)
where the adaptor joins the connector. Also the connector is starting
to rust. I'm not sure what else I can do to stop the leaking, but I'd
like to have a dry connection so my installation doesn't result in a
quicker corrosion than would normally happen. Should I use pipe dope
instead? Any suggestions would be appreciated.

Also, the heater came with a blue and white tab inside the connections.
The parts list calls these "Heat Trap Inserts (Inlet and Outlet)."
Are these needed and will they stop the leaking?