pipe dope on hot water heater

[CEPenworks]

So I just replaced my hot water heater and the female threaded fitting going onto the dielectric nipple coming out of the water heater will not seal up. I first reused the old one then when that leaked I got a new one. Our code requires hard pipe so no easy flex trials so each time I want to change something I have to cut the pipe again. On another water project earlier this year I had the same problem with a threaded connection. I ended up getting some T plus 2 pipe dope and that finally sealed it up. Is there any reason I can't use this on the water coming out of the water heater? I am also thinking I will get a slip union to put in this pipe just incase this takes some more trials.

[Stwood_]

Either dope or tape, I use what is handy. Usually tape as I have a big supply.

I wouldn't think twice about putting a union on those pipes.

[Phil Thien]

Sure you can use T Plus 2, that is exactly what I'd be doing. Tape doesn't work great on new threads unless both sides were cut by the same vendor, IMHO.

[John Mihich]

I have never replaced a WH without having to redo the hot water side.  I put pipe dope on them all the time and I still have to redo them - only the hot water side.

[Bluepine]

A good friend is a well driller, all joints get 2 wraps of Teflon and pipe dope. No call backs.

[jteneyck]

I have much better luck with pipe dope than tape.  I put unions and shut off valves in both the hot and cold lines to the hot water heater so swapping out the old for a new one, or dealing with a leak like you have, is less of a hassle.  

John

[fixtureman]

Can you not use a union so you don't have to cut the pipe

[CEPenworks]

I can't get a break with this project. I put on the union and applied pipe dope to the threaded connection to the water heater. The threaded connection leaked so at least I was able to disconnect the union and give the threaded connection a little more twist. Now I noticed the union is weeping just a little. I am thinking of loosening the nut and wiping some pipe dope around where the two pieces come together. I hope that will finally seal this thing up.

[Snipe Hunter]

Rector Seal - Tru Blue

[DustyDan]

I have had unions leak before, an ocasional drip.

My fix was to give it a few days and the leak creates enough corrosion to "heal" the leak.  This is only a once in  a while sort of thing. Not very professional but when ample tape and tightening doesn't seem to work it went away on it's own.