I am getting corrosion on my hot water tank connections that looks like electrolysis. I have a water purification system and it has been tested and working properly. I have a lightning protection ground wire that is connected to the copper piping that leads to the hot water tanks, Can this cause electrolysis?enter image description here

  • Do you have a dielectric union as the fitting connecting the water line to the heater? Is it happening to both pipe connections? It may be worth installing some dielectric unions to keep the two different metals away from each other.
    – Edwardt
    Jan 26, 2016 at 19:58

1 Answer 1


Yep, that's electrolysis alright. Edwardt is right, you need a Dieletric Union to stop it & it should've been standard practice by whomever chose to do garbage work & guarantee a new water heater very prematurely.

That T & P valve on top might be shot too, which shouldn't be there anyway & was only used as an elbow. If it's from the same guy or firm that did the insulation, then find a new guy or firm...they're absolutely horrible & not even up to hack level work.

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