A.O. Smith VB/VW- 1000 Boiler User Manual


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34
The boiler should be located in an area that is inaccessible to
the general public.
Never allow small children to use a hot water tap or to draw their
own bath water. Never leave a child or handicapped person unat-
tended in a bathtub or shower.
TABLE 8. Risk of Scalds.
Water Temperature
TimetoProduce2nd&3rdDegree
Burns on Adult Skin
Over170°F(77°C) Nearly instantaneous
160°F(71°C) About 1/2 second
150°F(66°C) About 1-1/2 seconds
140°F(60°C) Less than 5 seconds
130°F(54°C) About 30 seconds
120°F(49°C)orless More than 5 minutes
SHOULD OVERHEATING OCCUR OR THE GAS SUPPLY FAIL
TO SHUT OFF, TURN OFF THE MAIN MANUAL GAS SHUTOFF
VALVE TO THE APPLIANCE.
The operating temperature of the boiler must be maintained as
follows:
 • 120°F(49°C)orhigherinletwatertemperaturetotheboiler.
 • 20°F(11°C)differentialbetweentheboiler’sinletandoutlet(e.g.120°F
[49°C]inlet,140°F[60°C]outletminimumdesigntemperatures).
Iftheinletwatertemperatureintotheboilerislessthan120°F(49°C),
adjustments on the water bypass and the outlet valves at the rear
of the boiler, see Figures 14 and 15, are required; wait at least
one minute between adjustments for the temperature to stabilize.
1) Ifnecessary,throttledown(close)thewateroutletgate/ball
valveuntilthedesiredoutletwatertemperature(120°F[49°C]
minimum)isreached.Waitoneminute.
2) Notetheoutletandinlettemperatureindicatorreadings.
a) Iftheinletwatertemperatureislessthan120°F(49°C),
open,insmallincrements,thebypass(balancing)valve
untiltheminimum120°F(49°C)inletwatertemperature
or20°F(11°C)differential,whicheverhasthehigherinlet
temperature, is attained.
b) Iftheinletwatertemperatureisgreaterthan120°F(49°C)
andthe20°F(11°C)differentialisnotpresent,closethe
bypassvalveuntilthe20°F(11°C)differentialisattained.
NOTE: It may be necessary to make further adjustments on
the outlet and bypass valves until the desired inlet and outlet
water temperatures are reached.
MANIFOLD PRESSURE CONNECTIONS
Take the manifold pressure, refer to Table 1, by removing
thepipeplugandinsertingasuitable1/8”NPThosebarbfor
connection to the manometer/pressure gauge. Upon completion
of measurements and adjustments, remove the hose barb
and replace the pipe plug. Check for gas leaks and insure all
connections are gas tight, see Figure 19..
WATER TEMPERATURE REGULATION
HOT WATER CAN SCALD: Boilers are intended to produce hot
water. Water heated to a temperature which will satisfy space
heating, clothes washing, dish washing and other sanitizing needs
can scald and permanently injure you upon contact. Some people
are more likely to be permanently injured by hot water than oth-
ers.Theseincludetheelderly,children,theinrmorphysically/
mentallydisabled.Ifanyoneusinghotwaterinyourhomets
into one of theses groups or if there is a local code or state law
requiringaspecictemperaturewateratthehotwatertap,then
you must take special precautions. In addition to using the lowest
possibletemperaturesettingthatsatisesyourhotwaterneeds,
a means such as a mixing valve should be used at the hot water
taps used by these people or at the hot water supply tank. Mixing
valves are available at plumbing supply or hardware stores. Fol-
low the manufacturer’s instructions for installation of the valves.
Before changing the thermostat setting on the hot water system
controller, see Table 8.
Hot water temperatures required for automatic dishwasher
and laundry use can cause scald burns resulting in serious
personal injury and/or death. The temperature at which injury
occurs varies with the person’s age and time of exposure. The
slower response time of children, aged or disabled persons
increases the hazards to them. Never allow small children to
use a hot water tap, or to draw their own bath water. Never
leave a child or disabled person unattended in a bathtub or
shower.
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