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11. Before operating the heater, test the complete gas
supply system and all connections for leaks using
a soap solution.
Since some leak test solutions (including soap and
water) may cause corrosion or stress cracking, rinse
the piping with water after testing.
2.7.2 Special Precautions
for Propane Gas
Liquefied petroleum (LP) gas is heavier than
air. Therefore, do not install heaters using LP gas in
a pit or locations where gas might collect. Locate
heaters a safe distance from LP gas storage and filling
equipment. Consult local codes and fire protection
authorities about specific installation restrictions.
2.8 Electrical Wiring
Electrically ground the heater in accordance with
the latest edition of the National Electrical Code,
ANSI/NFPA 70. In Canada, use C22.1. Do not rely
on the gas or water piping to ground the metal
parts of the heater. Often, plastic pipe or dielectric
unions isolate the heater electrically. Service and
maintenance personnel who work on or around the
heater may be standing on wet floors and could be
electrocuted by an underground heater.
1.
Check heater wiring and pump for correct
voltage, frequency, and phase. Check to make
sure heater is wired for 120 volts alternating
current (VAC). If 240 VAC, contact local factory
representative or Bradford White.
2.
Wire the heater and pump exactly as shown in
the wiring diagram supplied with the heater.
See Figure 26 and 27 for a typical example of a
wiring diagram.
3.
Electrically interlock the pump and heater so
the heater cannot come on unless the pump is
running.
4.
Connect all field-installed devices (draft
switches, relays, timers, outdoor temperature
reset devices, etc.) to the heater wiring at points
labeled Field Interlock (see Figures 26, 27, 28
and 29).
Caution
WARNING
2.9 Combined Space Heating/Potable
Water Heating Systems
2.9.1 Combined Space Heating
NOTE: These systems are not allowed in the
Commonwealth of Massachusetts.
Piping and components connected to this water
heater for the space heating application shall be
suitable for use with potable water.
Toxic chemicals, such as used for boiler
treatment, shall not be introduced into the potable
water used for space heating. Do not use solder
containing lead in the potable water lines.
This water heater when used to supply potable
water shall not be connected to any heating system
or components(s) previously used with a non-potable
water heating appliance.
When the system requires water for heating
at temperatures higher than required for other
uses, an anti-scald mixing or tempering valve (see
Figure 25) shall be installed to temper the water
for those uses in order to reduce scald hazard
potential. Some jurisdictions may require a backflow
preventer in the cold water line. In such cases, the
temperature and pressure relief valve may discharge
water due to expansion. A diaphragm type expansion
tank will normally eliminate this condition. Follow
the manufacturer's instructions for installation of the
expansion tank.
SECTION 3.
Operating Instructions
3.1 Normal Operating Sequence
NOTE: Safe lighting and other performance
criteria were met with the gas manifold and control
assembly installed on the heater during tests specified
in ANSI Z21.13.
Mixing Valve
Hot Water
From Water Heater
or Storage Tank
Figure 25. Installation of tempering valve.
BRADFORD WHITE
Out —
Mixed Water
For Potable Use
Cold Water
Supply
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