<<Here in suburban Chicagoland,
I love that term - I watch a lot of WGN reruns on cable so I always end up
watching the "Chicagoland" news inadvertently. The first time I heard the
term, I thought they were talking about some sort of amusement park.
<< there is almost always a rash of municipal water main breaks after a good
cold snap, due to the water mains shrinking due to the scold temperatures
that get down to the level of the installed pipes.>>
That was another question I had - how long does it take to "cold soak" the
ground. I've read alot about freeze lines but these pipe ruptures seem to
be occurring well below that level.
<< Unless there are some strain reliefs periodically, the shrinkage causes
stresses and the weakest one breaks. Stress relief usually takes the form
of an "S" bend periodically.>>
I don't know whether it's still true, but I recall seeing on TV that some
municipal water systems are so old they are still using wooden mains. I
guess I should ask Google.
<<CHELAN, Wash. - It has been 2,000 years since the Romans built their
aqueducts, and 200 years since Philadelphia began using cast-iron water
mains. But the 6-inch-wide city pipe that still delivers drinking water to a
block on Nixon Street here uses an even more primitive technology: wood. . .
Water officials say they believe that a handful of wooden water mains are
still in use in South Dakota, Alaska and Pennsylvania, among other places.
The old wood pipes offer a vivid reminder of the age and fragility of the
nation's drinking water systems, many of which rely heavily on old pipes
that often remain out of sight and mind - until they burst.
And they are bursting with alarming frequency in many areas these days,
particularly in systems coping with septuagenarian, octogenarian, and even
century-old pipes. There are an estimated 240,000 water main breaks each
year in the United States, according to the Environmental Protection Agency'
s Aging Water Infrastructure Research Program, and some water experts fear
that the problem is getting worse. >> Source:
When the water main on my street broke last week, the water people had a
prerecorded message on their emergency number saying they were working on
several large breaks in the area. So it does seem to follow the cold
weather. Repairing broken mains can't be fun to do when it's 15F and windy
It turns out that a lot of "schmutz" got into the water pipes. I spent some
time today clearing out some nasty looking debris from the screens in the
bathroom and kitchen faucets. It seems the showerhead got hit, too. )-:
Probably time to consider a whole-house water filter. When I first moved
in, I found an acorn lodged in the kitchen faucet.
If NASA had a little foresight about the problems of cold weather, they
might not have dropped the Challenger into the ocean. If the USN had
realized what happens to ballast blow valves (as they were designed before
1963) at depth (they froze solid) the Thresher might not have sunk.
What I am concerned about is limiting the delta between the incoming very
cold water and the much warmer tank interior. There are several ways to go
I've already taken one step, which is to reduce the incoming pressure to the
whole house. That slows down the amount of water that can enter the water
heater and reduces the potential thermal stress.
I'm also going to turn the water heater's thermostat down just to lower the
over all temperature differential. The cooler the WH output, the lower the
delta between incoming and outgoing water.
A third action is to trim the hot water feed valve to the washing machine so
that it doesn't draw anywhere near the GPM of a wide open valve. It will
take longer to fill (will be measuring that as we do laundry) but it's not a
very big thing to wait an hour instead of 30 minutes for the laundry to be
done. It's not like I am outside in the bitter cold beating the clothes on
river rocks. (-:
A fourth action will be to avoid the HOT only wash cycle during bitter cold
months (we typically wash our LBL dog's blanket in hot water), thus further
slowing down the amount of cold water that's introduced into the tank
quickly and lowering the thermal "shock" to the heater.
If I wanted to spend money, I might look into a pre or post water heater
expansion tank or put aluminum fins on the pipe leading from the master
intake to the water heater. That's at least 25' feet of copper pipe that
could transfer some room heat into the incoming water, but I think that's
I think reducing the pressure and the temperature while taking care not to
draw enormous amounts of hot water will substantially reduce the thermal
differential and the risk of catastrophic failure from thermal stress. It
will be just my luck that it fails as a result of crud getting into the
lines from the recent water main break, but at least I will have tried. (-:
Robert Green;3195907 Wrote:
> I am wondering if prolonged cold spells substantially reduce the
> temperature of the water entering a house from the city water service .
> . .
They definitely do.
Winnipeg gets it's water from Shoal Lake, which is a lake in the
Whiteshell Provincial Park about 60 miles from Winnipeg.
If you have a single lever shower faucet, just take note of what the
faucet handle position is in summer and in winter. The hot water in
your water heater will be the same temperature (or close to) year round,
so that the difference in handle positions is entirely due to the warmer
cold water in summer and colder cold water in winter.
Water main breaks aren't caused by the pipe shortening due to thermal
contraction in the cold. Normally, in winter, the ground freezes to a
certain depth which we call the "frost line". Water supply pipes and
sewer lines will be buried well below that frost line so that the water
in the pipes doesn't freeze. But, what happens is that as moisture in
the ground freezes and expands AT the depth of the frost line, ice
"lenses" form. They are called ice lenses because of their shape; being
thickest in the middle and thinnest at the edges. These ice lenses are
very localized, typically being no more than about 100 feet in diameter.
It's the downward pressure exerted by the water as it freezes to the
bottom of the ice lens and expands that causes water pipes to break
underground. The force of water expanding as it freezes is pushing down
on the pipe one place, and as little as 30 or 40 feet away, you don't
have that pressure, and so the pipe bends until it breaks.
Here in Calgary, most house has water pressure gauge set at 60 psi when
water is running. Winter/summer, no difference. Our pipes are minimum
6 feet below ground. Is some one paranoia of something? Water heater is
designed to work normal under normal conditions. I wouldn't worry and
fiddle with it. If some one wants to experiment to prove some thing,
it'll take at least for the life of water tank with every thing
observed/measured documented. Also water main butrssting in cold weather
is due to rather from the ground heaving than freezing water
causing water lens.
It depends upon where you live and the source of the city water.
If you live somewhere that has wide swings of temperature from season to
season the water temperature will also vary and the anount of variation
would change with ground water depth. If the source is surface water as
opposed to ground water it will vary even more. FWIW, the water in Honolulu
(ground water) varies about 2 degrees between winter and summer.
I would think that temperature variation also depends upon how the water is
stored, transmitted and the overall rate of use. For example, if you live
somewhere that uses ground water but provides a head to it via elevated
storage tanks, the ground water temperature is going to change in the
storage tank, colder in the winter, warmer in the summer; however; if the
water in the tank is being used and replenished rapidly, that variation
would be minimized.
I get my water (central Florida) from my well which is about 110'. At the
moment, I set my single handle shower mixer at about 10:30; come August, it
will be at 1:30 so there is considerable temperature variation in the
source, no idea how much in degrees.
On Mon, 10 Feb 2014 11:40:30 -0500, "Robert Green"
I'm sure. The water coming from the cold water faucet is colder in the
winter than in the summer. And I've noticed it's even colder this
People often use "stress" or "strain" to talk about machines. I think
it rarely applies. The water heater elements are on more if the input
water is colder. If the elements are going to wear out, they wear out
that much sooner.
Sounds about right.
You can put the thermomenter in a short glass of water and watch the
temperature as the running water replaces the water in the glass and see
how long it takes until the temp stops dropping. (I know, ony part of
the overflow is old water, but you can figure it out.)
I disagree. Dad was a materials science engineer for the Navy and spent
lots of time deliberately stressing equipment to determine its failure
point. Thermal stress testing is an integral part of manufacturing.
Virtually every device I know of has specified high and low temperatures of
operation listed in the manual. That's because so many things behave
differently in the extreme cold (plastic gets brittle, batteries fail) or
heat (plastic becomes soft and batteries boil over) than they do at normal
Will give you some idea how much study is devoted to the topic. It's a
whole separate branch of mechanical engineering AND materials science.
Water heater tanks expand and contract as the internal temperature changes
and each expansion causes a slight degree of fatigue on the metal. The
greater the difference between the tank interior temperature and the inlet
water temperature, the greater the stress on the materials involved. Put on
some goggles. Go take a plain glass bottle, fill it with boiling water and
plunge it into 41F water. That concludes today's demonstration of thermal
Am I being overly cautious? Maybe. But with a water main breaking on the
street in the same week my neighbor's water heater failed, I've got a right
to be a little worried.
And that temperature difference results in increased mechanical stress on
the elements as well because they are contracting and expanding more than
then do with warmer inlet water. It's not just the number of extra cycles,
it's the exposure to far greater cold than usual. The greater the delta,
the more mechanical stress on the elements and every other component of the
That's true, of course but the current weather conditions are subjecting an
old tank (it's 18 years old) to stress levels not seen during its long
service life. I'm perfectly comfortable with the assumption it needs to be
replaced soon. But I want that to be in the warmer weather. Changing it
out right now would be drastic, expensive and foolish because it's
impossible to get a bargain from a plumber on parts or labor because the
current demand is nearly insatiable. My neighbor had to call 10 places to
find one that one do it the NEXT day and even they lied to him. It took two
I've got a working water heater now showing no signs of distress other than
the noises it was making when I initiated a 20G fill of all hot water for
the washing machine. I considered that a clue that it might be a good idea
to throttle back the heat setting and the water pressure for now to reduce
how drastic the change of temperature is within the tank.
It's taken hours to explain it but less than a minute to do. Despite the
assurances I'm wasting my time, very little of it was actually consumed and
no one, except Vic, has provided a reason (possible valve failure) why
someone shouldn't reduce the temperature setting and trim the inlet flow
until the weather and the inlet water temperature warms up.
Despite the surprising amount of resistance I've been reading, I am sure at
least one person's already either turned down the heat or the water flow -
just to be on the safe side. (-:
FWIW, just a few degrees outside of normal operating range can have drastic
<<Constance Tipper of Cambridge University demonstrated that the fractures
were not initiated by welding, but instead by the grade of steel used, which
suffered from embrittlement. She discovered that the ships in the North
Atlantic were exposed to temperatures that could fall below a critical point
when the mechanism of failure changed from ductile to brittle, and thus the
hull could fracture rather easily.>>
The SSN Thresher was also the victim of the cold, but in a more obtuse way:
<<When the high pressure air that was used to blow the tanks left the
storage banks, it passes through the control valves that keep it in the
banks under pressure. Anytime a compressed gas expands, it cools rapidly. As
the very cold air passed through the valves, frost began to form due to the
presence of moisture in the air. It very quickly built up (a matter of a few
seconds) and froze solid in the valves. The solid ice stopped the air just
as effectively as shutting the valves, thus the Thresher was unable to blow
I would never underestimate the effects of extreme heat and cold on
mechanical systems. Hell, I drove a Jag MarkX that had a terrible tendency
to overheat in warm weather and the only way to stop it was to shut off the
A/C, pop up the bonnet air scoop and run the heater full blast. That was
usually in the middle of the hottest days in the summer. It's been my
experience that cars designed outside the US don't quite operate as they
should in the climate extremes of the US. It took a long time for the
Japanese to understand the need for Desert Valley cooling capacity in
Of course, when you consider the VW Bug's absymal heating system, it might
be true that some cars just didn't operate as they should *anywhere*
regardless of climate. You would think with all that snow and cold, they
should have built a working heater.
Speaking of snow and cold, it's 2AM in DC and it's snowing like a mother.
pressure tanks are installed to protect water heaters and prevent pressure
release valves opening when water mains have a check valve so water from sa
y a swimming pool being filled cant siphon back in the mains and add contam
inated water to the main in case of a water main break......
<pressure tanks are installed to protect water heaters and prevent pressure
release valves opening when water mains have a check valve so water from say
a swimming pool being filled cant siphon back in the mains and add
contaminated water to the main in case of a water main break......>
But I don't have a swimming pool! And I obviously don't have a check valve
on the water line coming into the house because the recent water main break
completely drained the house water lines. That wouldn't have happened with
a check valve in place.
I expect I'll have to call the county inspector to find out why the
expansion tanks are now required by code.
I do beleve in common sense actions to protect homes.
but all this effort to protect a old water heater might be over kill...
if its that old its probably best to just replace it before failure.
of course I tend to replace car batteries befor they leave me stranded, and old water heaters before they leak......
in both cases its better to replace when cnvenient for me, rater than waiting for a big leak or getting stranded when in zero weater a vehicle wouldnt start..
incidently I discovered replacing car batteries at 4 years old helps prevent alternator failures.
but one can spend so much time and effort trying to get the longest life out of everything its just not worth the effort..
"All this effort?" I turned the main shut off valve less than half a turn.
Then I turned the water heater temp control less than 30 degrees. Why do
people assume there's all this effort involved? I have to wonder.
I didn't have to eat my sled dogs or ponies on the perilous journey to the
basement because I ran out of food like Captain Scott:
Cutting back on both the operating temperature and overall water pressure
took all of one minute. Jeez. Where's all the effort some people seem to
believe is involved in trying to protect an old water heater from some very
unusual weather conditions? To me it's just elementary to try to
compensate for conditions that the water heater has never before faced over
its entire service life and will never likely face again.
Just remember how many people in authority poo-pooed the engineers that
recommended that Challenger's flight be postponed until the very rare cold
snap had ended. Extreme cold weather has consequences. In NASA's case,
Trying to reduce the effect the extreme cold might have on an old water
heater seems to me to be simply prudent behavior, especially since the steps
I took were so damn easy. Twisting a valve and a dial both less than 1/2 a
turn. What is it that Trader says?
"Good grief!" (-:
I wait until a tank breaks. The tank will just leak down into the
floor drain. A bad battery shows up in the winter. Slow crank.
Last one I bought lasted at least 6 years. Car broke down first, then
my son put it in his car.
Water heater was here when I bought the house, then it lasted
15 more years.
I have put in a couple alternators, but don't think it was
battery-related. Batteries tested okay.
GM cars don't have long lasting alts.
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