I live in gulfcoast Florida and have been plagued by persistent (1-2
per year) pinhole leaks in the copper pipes in our home (1990). One
interesting aspect is that, so far, all the pinhole leaks have occurred
in cold-water lines. I am not sure what that may indicate, but,
perhaps, someone has an opinion.
I have read many of the posts concerning the many theories for the
causes of this problem, i.e., acicidity, electrical currents,
chemicals, minerals, etc. Regarding possible electrolysis and stray
electrical currents, I installed a new grounding rod on the main
electrical box outside the house (right near where the water line
enters, incidently). However, I noticed that my second-floor electric
water heater is grounded to the copper piping adjacent to the heater.
Having read a lot of posts commenting on the need to isolate electrical
currents from the water system, why would a water heater be grounded to
the water pipes? Does this make sense? Should it be changed?
Any suggestions for diagnosing and/or addressing this pinhole problem
would be appreciated.
Probably something in the water. A water heater has an anode (think that is
the correct name) in it that is made to be eaten away by the chemicals in
the water. It is a rod of special metel that is usually attached to a pipe
plug that goes into the water of the tank. Saves the tank. By now yours is
probably just about gone.
The other poster had a good idea changing the anode in the water heater.
All appliances, loads should be grounded to the service by use of an
conductor. Not by using a water pipe. Suggest you run a proper circuit to
the water heater.
Stop guessing and try to find someone who has the equipment that can measure
the ground system. Amec makes a meter for ~$2k. Measures both ohms and
volts. Get a decent VOM meter and start taking some measurements. Sadly
this could get really expensive to find.
A plumber I see from time to time on different jobs once told me about bad
copper piping coming out of Mexico. He said that on one job that he used
the stuff many pinholes showed up after the system was pressurized. Perhaps
you have crummy pipes. Do your neighbors have similar problems? You could
also have your water tested to see if that is a contributing factor.
Regarding the upstairs water heater being grounded to the water pipe, I
suggest that you leave it alone. It may not be a grounding connection, but
it may be a bonding connection. I doubt that electrical current on your
water pipes is causing the pin holes to develop.
On Sat, 29 Oct 2005 22:04:52 -0400, "John Grabowski"
Everything other replies have said is true.
Seriously, get your water tested. The cost is minimal. You want to
find out how acidic your water is. Acidic water eats up pipes. If it
is, you might want to replace your pipes with pvc. If all the leaks
keep occuring in the same section of piping, it could just be bad
pipe(s). In other words, bad from the factory. If this is the case
adn your water is not too acidic. Just replace that entire section of
pipe. The fact it's only happening to your cold pipes tells me that
bad pipes are indicated in that part of the house.
One other thing, lightning. I have seen it happen first hand. A bolt
of lightning hits in the area, travels down a copper pipe, and blows a
small hole in the pipe (usually right near a turn in the pipe). This
is an actual problem that really does occur in rare cases, (but not as
rare as I once thought, because I have seen it happen several times
GROUND that water heater with WIRE. Use #6 or thicker wire and run it
to your ground rods. The copper pipes are already grounded to the
water heater anyhow, unless they are isolated by dielectric unions.
Bond the pipes WITH WIRE to the ground rods too. That also helps with
One last thing to look at. Do you have a combination of copper and
steel pipe? Or have copper touching aluminum or other metals
somewhere in the system? All of that can cause corrosion. If
connected to steel pipes, use dielectric unions. If touching other
metals, place plastic or tape in between.....
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