Replace Electric Water Heater?

[Lin]

Our 10 gallon electric water heater has developed a ring of rust around the seam at the bottom.  Although I am not finding any water on the outside of the heater, am I right in guessing that that the tank is leaking and I should replace the unit?

[white-eagle]

admittedly, i am not one of the experts on this board, but i'd check for a leaky pressure valve seeping, maybe put some paper towels down around the top and underneath to see if they show wetness.  paper towels wilt up if they get wet, even if they are dry later.  anytime i touch a water anything, i put towels around to make sure it's not dripping somehow.  The seeping valve can be burped so it won't seep.something about turn the heater off, turn the water off, drain it to clean it out with pressure valve open?, then turn the water back on with faucet open somewhere.  i think that's the procedure.
also, the humidity has been really high, and you may just have a moist area.
but if it's an old hwh, then you might just want to bite the bullet and get a new one.
my 2 cents and worth everything you paid for it.

[Lin]

Interesting, although I have not seen any dripping from the release valve, the rust is definitely richest below it.  Actually, I just checked and there is no rust on the seam on the far side of the heater.  I will put a rag in the valve and see if it gets moist. Thanks

[FloridaCliff]

Lin,

That is just the outside cover, there is actually a layer of insulation behind it, then the actual tank.

You may have a leak, but those seams are subject to rusting.

That is a point of condensation to the cooler external air.  I have seen lots of ones just as you describe that were fine.

Of course now that I've said that, yours will spring a leak. (just kidding)

You should check for leaks near the element(s) or any other point of egress.

Best of luck,

Cliff

[TomC]

10gal electric water heater at Home Depot is about $260.00. I use two-with one plumbed into the next with the final one powered through the inverter for hot water going down the road. Mine have been in since 1994 without any problems. Can hardly beat that. Good Luck, TomC

[Lin]

It looks like White Eagle was right.  A rag in the release valve gets damp.  I guess I will clean up the rust, etc. and may have to replace the valve.

[bs4104]

Will this help?

[white-eagle]

lin,
glad i was right, but it may be too early to replace the valve.  google on fixing the air pocket in a hot water tank.  apparently, if there is no air pocket to allow for expansion, then heating up the tank will cause the valve to release pressure as it is supposed to.  it's easier to just drain the tank down, maybe getting rid of debris in the bottom, and restore the expansion bubble in the tank.  replacing the valve and not fixing the bubble will result in more leakage.

[06 Bill]

It is my understanding that there should not be any air in hot water tank itself. If your system has a
check valve in the cold water supply line then an expansion tank is nesc. between the hot tank and the
check valve. If no check valve present then the expanded hot water merely backs up the feed line no
expansion tank nesc. 06 Bill

[Lin]

I must say that I am continually reminded of my own foolishness.  Because of the issue discussed previously, I decided that the in and out connections to the water heater would be best off replaced.  These connections are copper tubing with compression fittings going to a brass adaptor, threaded PVC elbows, and finally the male pipe coming from the heater.  Well, I replaced things just as they were.  After tightening everything up and filling the tank with water, I wanted to tighten the connections around the PVC elbow since there was some sign of water.  "Careful," I says to myself, "you don't want to over tighten and break the PVC."  That's when I realized the dumb error.  I could have used galvanized elbows!  I hope this teaches me a lesson, but I somehow doubt it.

[bevans6]

Brass elbows maybe if you want to use metal, but I've stopped using galvanized for anything that carries water if I can possibly help it.  I am so tired of fixing stuff that is rusted to oblivion because the previous guy in used the galvanized pipe fittings.

Brian