State GS6 75 URRBS - Manual (Page 10)

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6. Louvers and Grilles: In calculating free area, consideration shall be given
to the blocking effect of louvers, grilles or screens protecting openings.
Screens used shall not be smaller than 1/4 inch (6.4 mm) mesh. If the
free area through a design of louver or grille is known, it should be used
in calculating the size opening required to provide the free area specifi ed.
If the design and free area is not known, it may be assumed that wood
louvers will be 20-25 percent free area and metal louvers and grilles will
have 60-75 percent free area. Louvers and grilles shall be fi xed in the
open position or interlocked with the equipment so that they are opened
automatically during equipment operation.
7. Special Conditions Created by Mechanical Exhausting or Fireplaces:
operation of exhaust fans, ventilation systems, clothes dryers or
fi replaces may create conditions requiring special attention to avoid
unsatisfactory operation of installed gas utilization equipment.
FIGURE 8A.
WATER PIPING
HOTTER WATER CAN SCALD:
Water heaters are intended to produce hot water. Water heated
to a temperature which will satisfy space heating, clothes washing,
dish washing, cleaning 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 others. These include
the elderly, children, the infi rm, or physically/mentally handicapped.
If anyone using hot water in your home fi ts into one of these groups
or if there is a local code or state law requiring a certain temperature
water at the hot water tap, then you must take special precautions. In
addition to using the lowest possible temperature setting that satisfi 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 water heater, see
Figure 2. Valves for reducing point of use temperature by mixing cold
and hot water are also available. Consult a qualifi ed installer or
service agency. Follow manufacturer’s instructions for installation
of the valves. Before changing the factory setting on the thermostat,
read the “Temperature Regulation” section in this manual.
INSTALLING THE NEW WATER HEATER
This water heater shall not be connected to any heating systems or
component(s) used with a non-potable
These water heaters cannot be used in space heating applications only..
All piping components connected to this unit for space heating
applications shall be suitable for use with potable water.
Toxic chemicals, such as those used for boiler treatment shall not be
introduced into this system.
When the system requires water for space heating at temperatures
higher than required for domestic water purposes, a mixing valve must
be installed. Please refer to Figure 2 for suggested piping arrangement.
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 fl ow 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 in the water
system. Expansion tanks are available for ordering through a local
plumbing contractor. Refer to the “Thermal Expansion” section in this
manual and/or contact the local water supplier and/or a service agency
for assistance in controlling these situations.
NOTE: To protect against untimely corrosion of hot and cold
water fi ttings, it is strongly recommended that di-electric unions
or couplings be installed on this water heater when connected
to copper pipe.