State SBB75 76NE - Manual (Page 7)

7
THERMOMETERS (Not Supplied)
Thermometers should be obtained and field installed as shown in
Figure 3.
Thermometers are installed in the system as a means of detecting the
temperature of the outlet water supply.
COMBINATION WATER (POTABLE) HEATING
AND SPACE HEATING
1. All piping components connected to this unit for space heating
applications shall be suitable for use with potable water.
2. Toxic chemicals, such as those used for boiler treatment, shall
NEVER be introduced into this system.
3. This unit may NEVER be connected to any existing heating system
or component(s) previously used with a non-potable water heating
appliance.
4. When the system requires water for space heating at temperatures
higher than required for domestic water purposes, a tempering
valve must be installed. Please refer to installation diagram on
page 6 of this manual for suggested piping arrangements.
5. These water heaters cannot be used in space heating applications
only.
CAUTION
A closed system will exist if a check valve (without bypass), pressure
reducing valve (without bypass), or a water meter (without bypass)
is installed in the cold water line between the water heater and street
main (or well).
Excessive pressure may develop in such closed systems, causing
premature tank failure or intermittent relief valve operation. This is not a
warranty failure. An expansion tank or a similar device may be required
in the inlet supply line between the appliance and the meter or valve to
compensate for the thermal expansion of the water.
SYSTEM CONNECTIONS
The system installation must conform to these instructions and to the
local code authority having jurisdiction. Good practice requires that all
heavy piping be supported.
RELIEF VALVE
This water heater is equipped with a combination temperature-pressure
relief valve that complies with the standard for relief valves for hot water
supply systems Z21.22-CSA 4.4. FOR SAFE OPERATION OF THE
WATER HEATER, THE RELIEF VALVE(S) MUST NOT BE REMOVED
OR PLUGGED.
ASME ratings cover pressure relief capacities. ANSI ratings cover release
rate with temperature actuation.
In addition to the appliance relief valve, each remote storage tank
which may be used in conjunction with this appliance shall also be
installed with a properly sized, rated and approved combination
temperature (ANSI) and pressure (ASME) relief valve(s). This valve
shall comply with the standard for relief valves for hot water supply
systems Z21.22-CSA 4.4.
WARNING
THE PURPOSE OF RELIEF VALVE IS TO AVOID EXCESSIVE PRESSURE
OR TEMPERATURE INTO THE STEAM RANGE, WHICH MAY CAUSE
SCALDING AT FIXTURES, TANK EXPLOSION, SYSTEM OR HEATER
DAMAGE. NO VALVE IS TO BE PLACED BETWEEN THE RELIEF
VALVE AND TANK.
Your local code authority may have other specific relief valve
requirements.
A DRAIN LINE MUST BE CONNECTED TO THE RELIEF VALVE TO
DIRECT DISCHARGE TO A SAFE LOCATION TO AVOID SCALDING OR
WATER DAMAGE. THIS LINE MUST NOT BE REDUCED FROM THE
SIZE OF THE VALVE OUTLET AND MUST NOT CONTAIN VALVES,
RESTRICTIONS NOR SHOULD IT BE LOCATED IN FREEZING AREAS.
DO NOT THREAD OR CAP THE END OF THIS LINE. RESTRICTED OR
BLOCKED DISCHARGE WILL DEFEAT THE PURPOSE OF THE VALVE
AND IS UNSAFE. DISCHARGE LINE SHALL BE INSTALLED TO ALLOW
COMPLETE DRAINAGE OF BOTH THE VALVE AND LINE.
See SERVICE INFORMATION section for procedure and precautions.
The type, size and location of the relief valves must be in accordance
with local codes. The location of the relief valve is shown in Figure 1.
The heater has a factory installed high temperature limit switch.
GAS PIPING
Contact your local gas service company to ensure that adequate gas service
is available and to review applicable installation codes for your area.
Size the main gas line in accordance with Table 4. The figures shown
are for straight lengths of pipe at 0.5 in. W.C. pressure drop, which is
considered normal for low pressure systems. Note: Fittings such as
elbows, tees and line regulators will add to the pipe pressure drop. Also
refer to the current edition of the National Fuel Gas Code. For Canadian
installations consult Canadian Installation Code CAN/CSA-B149.1.
WARNING
The minimum gas supply pressure for input adjustment is 6.0" kPa W.C.
for natural gas (11.0" kPa W.C. for propane).
THE HEATER IS NOT INTENDED FOR OPERATION AT HIGHER THAN
14" kPa WATER COLUMN SUPPLY PRESSURE. EXPOSURE TO HIGHER
GAS SUPPLY PRESSURE MAY CAUSE DAMAGE TO THE CONTROL
WHICH COULD RESULT IN FIRE OF EXPLOSION. If overpressure has
occurred such as through improper testing of gas lines or emergency
malfunction of the supply system, the control must be checked for safe
operation. Make sure that the outside vents on the supply regulators
and the safety vent valves are protected against blockage. These are
parts of the gas supply system not the heater. Vent blockage may occur
during ice storms.
IT IS IMPORTANT TO GUARD AGAINST GAS VALVE FOULING FROM
CONTAMINANTS IN THE GAS WAYS. SUCH FOULING MAY CAUSE
IMPROPER OPERATION, FIRE OR EXPLOSION.
IF COPPER SUPPLY LINES ARE USED THEY MUST BE INTERNALLY
TINNED AND CERTIFIED FOR GAS SERVICE. BEFORE ATTACHING THE
GAS LINE, BE SURE THAT ALL GAS PIPE IS CLEAN ON THE INSIDE.
TO TRAP ANY DIRT OR FOREIGN MATERIAL IN THE GAS SUPPLY
LINE, A DIRT LEG (SOMETIMES CALLED SEDIMENT TRAP OR DRIP
LEG) MUST BE INCORPORATED IN THE PIPING (SEE FIG. 5). THE
DIRT LEG MUST BE READILY ACCESSIBLE AND NOT SUBJECT
TO FREEZING CONDITIONS. INSTALL IN ACCORDANCE WITH
RECOMMENDATIONS OF SERVING GAS SUPPLIERS. REFER
TO THE CURRENT EDITION OF THE NATIONAL FUEL GAS CODE.
For Canadian installations consult Canadian Installation Code CAN/
CSA-B149.1.
To prevent damage, care must be taken not to apply too much torque
when attaching gas supply pipe to gas valve inlet.
Apply joint compounds (pipe dope) sparingly and only to the male threads
of pipe joints. Do not apply compounds to the first two threads. Use
compounds resistant to the action of liquefied petroleum gases.