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Start Up Conditions
THERMAL
EXPANSION
Water
supply
systems
may,
because
of such
events
as high
line pressure,
frequent
cut-offs,
the effects
of water
hammer
among
others,
have
installed
devices
such
as pressure
reducing
valves,
check
valves,
back
flow
preventers,
etc_.to
control
these
types
of problems.
When
these
devices
are not
equipped
with an internal
by-pass,
and no other measures
are
taken,
the devices
cause
the water
system
to be closed.
As
water
is heated,
it expands
(thermal
expansion)
and closed
systems
do not allow for the expansion
of heated
water.
The water within
the water
heater
tank expands
as it is heated
and increases
the pressure
of the water
system.
If the relieving
point of the water
heater's
temperature-pressure
relief valve
is
reached,
the
valve
will
relieve
the
excess
pressure.
The
temperature°pressure
relief
valve
is not
intended
for
the
constant
relief
of thermal
expansion,
This is an unacceptable
condition
and must
be corrected.
It is recommended
that any devices
installed
which
could create
a closed
system
have
a by-pass
and/or
the system
have
an
expansion
tank
to relieve
the
pressure
built
by thermal
expansion.
Thermal
expansion
tanks are available
from Sears
stores
and through
the Sears
Service
Centers.
Contact
the
local
plumbing
inspector,
water
supplier
and/or
the
Sears
Service
Center
for assistance
in controlling
these
situations.
Thermal
Expansion
Tank Specifications
Mode_
Number
153.331020
153.331050
Tank
Capacity
in Gals.
2
5
Dimensions
in hches
Dia.
Length
8
12 3/4"
11
14 3/4"
Pipe
Fittings
On Tank
3/4" Male
3/4" Male
HOT
(;OLD
WATER HEATER
(3)
COLD WATER
PRESSbRE
ruNLET FiTTiNG
REDUCING
II
VALVE
W,TH
m_
BY.PASS
H EXPANSION _
INLET COLD
PRESSURE GAUGE
WATER
SHUTOFF
RECOHHENDED iNSTALLATiON
(VERTICAL MOUNTmNG)
WATER HEATER
FLOOR, CEmUNG
COLD WATER
JOIST,ETC,
ruNLET Ft&tqQ N G
, #_$T_PPING
3
|1 II t
_
o)
_{ II U I
_
PRESSURE
_
II _ J
REDUCING
INLETCOLD
VALVEWmTN
WATER
(I)
BY-PASS
SHUTOFF
PRESSURE GAUGE
ALTERNATE
RECOHNENDED
iNSTALLATION
(HORIZONTAL
HOUNT_NG)
Expansion
Tank Sizing Chart
Operationa_
Conditions
SMELLYWATER
Expansion
Tank
Capacity
Needed
In_et*
Water
Pressure
40psi
50psi
60psi
70psi
80psi
Water
Heater
Capacity
(Gallons)
30
40
50
66
80
2
2
2
5
5
2
2
2
5
5
2
2
5
5
5
2
2
5
5
5
2
5
5
5
5
* Highest
recorded
inlet water
pressure
in a 24 hour period
or
regulated
water
pressure.
Note:
Expansion
tanks are pre-charged
with a 40 psi air charge.
If the inlet water
pressure
is higher
than
40 psi, the expansion
tank's
air pressure
must
be adjusted
to match
that pressure,
but must not be higher
than 80 psi.
Strange
Sounds
Possible
noises
due to expansion
and
contraction
of some
metal
parts
during
periods
of heat-up
and coo!-down
do not
represent
harmful
or dangerous
conditions.
2O
In each
water
heater
there
is installed
at least one anode
rod
(see parts section)
for corrosion
protection
of the tank.
Certain
water
conditions
will cause
a reaction
between
this rod and
the water.
The
most
common
complaint
associated
with
the
anode
rod is one of a 'rotten
egg smell'L
This odor
is derived
from
hydrogen
sulfide
gas dissolved
in the water.
The smell
is
the result of four factors
which
must al! be present
for the odor
to develop:
* A concentration
of sulfate
in the supply
water.
* Little or no dissolved
oxygen
in the water.
* A sulfate
reducing
bacteria
within
the water
heater.
(This
harmless
bacteria
is non-toxic
to humans.)
* An excess
of active
hydrogen
in the tank.
This is caused
by
the corrosion
protective
action
of the anode.
Smelly
water
may
be eliminated
or reduced
in some
water
heater models
by replacing
the anode(s)
with one of less active
material,
and then
chlorinating
the water
heater
tank
and al!
hot water
lines.
Contact
the local
Sears
Service
Center
for
further
information
concerning
an Anode
Replacement
Kit
#9001453
and this Ch!orination
Treatment.
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