Hey my line going from the expansion tank into the WH has the pressure fitting /nut on the WH end and solder off the expansion tank "t" fitting. This is a flex line and it has a slow drip/leak. (perfect for waterboarding)
The nut came off just fine but the solder will NOT let go.
Question - The tank is vertical & above the intake line. Is there water 'trapped' in the line via vacuum?
I have released the pressure from the expansion tank & still no dice.
The only way you can heat and unsolder that connection is if there is absolutely no water and it's open to air.
If you have a torch and a Male Adapter to solder back on, you can disconnect and bend the tubing downward to drain it out. Or just cut the pipe back behind the tubing and solder the MA there.
Some flex connectors with 3/4 ends will work then. NO TEFLON TAPE. The flex connectors with have seals at the ends.