Paul wrote:

Electric water heater is an A.O. Smith 40 gallon "low-boy" (short and fat)
about 10 years old. It's in a Florida condo unit, and from what I see, no
dielectric unions on the copper water lines to and from the heater. I see
a moderate amount of corrosion where the copper fittings connect to the
heater. No leaks. I don't see any rust or particles in the water at the
taps. I think it's a little slow to get hot water out, but not that
unreasonable.

Since this is a winter vacation place and I won't be there 24/7 I'm a little
nervous about the tank letting loose when I'm not there, although it is on a
first floor slab and a drain pan is installed...

If I do replace it, dielectric unions are supposed to be used, correct?

Home Depot's selection all seem to have only a 6 year warranty which seems
to be on the low end. Consumer Reports said that brand doesn't matter, that
the warranty does, i.e., more years = heavier duty tank linings, insulation,
etc.

Your input appreciated !

Thanks.

-- Paul


Here's my experience over some years. Copper male adapters
directly into the tank threaded bosses will corrode the boss
over time. I've seen them nearly dissolved.

Dielectric Unions work to prevent that failure, but they do tend
to foul up inside.

So-called dieletric "heater nipples" which have a smooth plastic
interior seem to be as effective as the unions and don't clog
as often.

Electric heaters last a long time but that varies with water quality.
Failure at the supply inlet/outlet isn't going to be caught by the
pan and you could have a mess. Your call...

Jim