Questions before getting a new water heater

[BadgerBoiler MN]

If there is no check valve in the main water, there is no need for an expansion tank. In Minnesota the code reads 18" for the terminal end of a WH T&P. Some codes state no more than 2' or less than 6".

[hearthman]

I'm referencing the 2009 IRC, P2803.6.1 : " The discharge piping service a pressure relief valve, temperature relied valve or combination valve shall-
item 10. Not terminate more than 6" above the floor or waste receptor".

For boilers, M2992.4 Pressure relief valve. "...Discharge shall be piped to drains by gravity to within 18" of the floor or to an open receptor."

Your local code may differ.

[pacnw]

I have seen and inspector required outside discharge of T&P.

Mobile homes, in my area, must be piped outside the skirt so it can be seen.

Some stick built homes are piped UP and OUT so they do not discharge in a finished basement.