Water heater hot outlet union leaking

dog193

Outlet has a 3/4 nipple screwed in, then a 3/4 metal (appears to be galvanized) union going into another 3/4 nipple soldered to copper piper.
Water started leaking from the union today. Tonight I disconnected, cleaned and used teflon tape on the threads of the union but it still leaks after two attempts.
Other than replacing the union are there any other suggestions?
Should I be using pipe dope instead of teflon tape?
Thanks in advance,
Jay in Illinois

tubguy

Exactly where is the union leaking. Where the two halves go together or on either side?

dog193

It's leaking around where the big nut joins the two pieces together, water is coming up through the threads.

Bondo

Ayuh,......

Those fittings seal against their Faces,... No need for Tape or Sealant.....

My 1st Guess is,... Your's has corroded or rusted,+ Probably needs to be Replaced.....

tubguy

It is odd that it started leaking out of the blue. You could try using pipe dope on the threads and use 2 big wrenches to tighten things back up. Hope it works.

Mike