- Q.I have an A.O. Smith water
heater with a faulty polypropylene dip tube. Your
report on dip-tube failures ( Notebook, 7/99)
said that a faulty dip tube may need to be replaced
with a new copper dip tube. However, the tech support
people at A.O. Smith told me that using a copper dip
tube will destroy my water heater, and is not
recommended. What’s the story?
A.Master plumber
Rex Cauldwell responds: The report was
mistaken in advising that defective polypropylene
dip tubes should be replaced with copper dip
tubes.
For those of us old enough to remember, dip
tubes were originally made of glass. Since they had
a habit of breaking during transit, the transition
to plastic was inevitable. And perhaps it was just
as inevitable that they would keep making them
cheaper until they failed. Most plastic dip tubes
have not had any problems. The only dip tubes with
reported failures are polypropylene dip tubes
manufactured by Perfection Corporation between
August 1993 and October 1996. More information on
the failures and the class-action settlement can be
found at www.diptubesettlement.com.
Failed dip tubes are repaired by either
replacing the water heater ( usually at your
expense) or by installing a new plastic dip tube
(usually at the manufacturer’s expense).
Copper dip tubes should not be used, for several
reasons. A copper dip tube would void the warranty
of the water heater. Corrosive water can attack a
copper dip tube. Finally, since copper is more
"noble" than a water heater’s anode rod,
the anode rod will die an early death, and so will
the steel water tank, as the tank tries to give
itself up to save the copper.