repeated corrosion on hot water outlet

clammy

Replace a standard 50 gal failed hot water heater about 2 years ago and it had a few years on it about 12 .Just happened to have a buddy who gave me a new warranty tank (ho wanted a bigger tank )i installed it all good n nearly 1 year pass and the tank developed a leak on the back side about 2/3 up . i pull it install a new warranty tank and now just about 1 year to the day the HO tells me they notice corrosion on the outlet di electric nipple ,i go and take a look and sure enough theres some corrosion .there is no visable leak at my connection or where the nipple is threaded into the tank .The tank is bonded just wondering i am going to re chk for stray voltage ,the home is on city water and it s not like theres 6 people there only 2 .Was planning on pulling the nipple and chking anode rod even though the first warranty tank s anode was near perfect and the tank had been flushed regularly .peace and good luck clammy

Larry Weingarten

Hi Clammy, It would be nice to see a photo of the corrosion, and location of the bonding wires. But one thought is that if you used a flex connector with dielectric built into the end, it's pretty common that the rubber washer in the end of the flex shrinks with heat and needs to be re-tightened after about six months. If it's bonded and grounded back to the main panel, you shouldn't be getting stray current problems. Any thoughts about the water quality?

Yours, Larry

clammy

Thanks larry no flex brass npt x copper sweet union bonding is about 6 to 8 inches above havent had time to change it out .i think it may have weeped past the plastic insert i ll have to see

hot_rod

get rid of the dielectric unions, the create more problems then they solve. Dielectric flex connectors, copper or braided stainless.

Is there a water softener? Softening increases the TDS and increases corrosion if you have any leak or seep at the joint.

MilanD

Check also upstream cold line. There may be break in the ground if softener or plastic filter housing was installed but not jumped/bonded over.

EBEBRATT-Ed

Not a plumber so I don't do water heaters except my own but I have walked by many and seen crusted up dielectrics.
A plumber buddy told me to put dielectrics on mine the last time I changed it. "your water heater will last forever"

I put them on, within a year the dielectric unions leaked. Maybe others love them but they don't work for me