Water Heater Replacement - How Do I Undo This Fitting?

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Sep 11, 2009
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My old AO Smith hot water heater is leaking and corroded. There is a pipe that goes through the wall, which I assume attaches to a drain somewhere, although I can't see what it connects to on the other side. This pipe is attached to the pressure relief valve. How do I undo this? I'm thinkin I will need to use a torch to unsolder the pipe from the fitting, as it doesn't look like the fitting can be rotated off. Is this correct?



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Were it I, I would use a pipe cutter and cut the pipe in the short straight section, just before it enters the wall. You can then use a fitting to couple to the new TPR.

I would also and a couple of 6" red brass nipples and full-port ball valves, so that the heater can be isolated, should other related repairs be needed.
What type of fitting would you suggest? Can I use a piece of flexible pipe? Thanks
Enclosed area 3 links to the proper installation, and as you will see, yours has some deficiencies. But specifically, since you do not know the location of the new HW heater TPR location, a flex line with an 100PSI rating may be appropriate and there are SHARK-BITE fittings to attach to the existing discharge line.


P2804.6.1 Requirements for discharge pipe.

TPR discharge is no joke. In fact, it is the most critical item on the w/h. Please heed Snoonyb's advice above this post.
Ii's already there, "#10. Terminate not more than 6 inches (152 mm) and not less than two times the discharge pipe diameter above the floor or waste receptor flood level rim."

An air-gap, is an anti-siphon device, so, 6" should do it.

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