John Wood Commercial - AJWSC - Manual (Page 12)

WATER SUPPLY
Piping Installation
Piping, fittings, and valves should be installed according to
the installation drawing (Figure 7). If the indoor installation
area is subject to freezing temperatures, the water piping
must be protected by insulation. Water supply pressure
should not exceed 80% of the working pressure of the water
heater. The working pressure is stated on the water heater’s
data plate. If this occurs, a pressure reducing valve with a
bypass should be installed in the cold water inlet line to the
entire system. This should be placed on the supply to the
entire structure in order to maintain equal hot and cold water
pressures.
Note: Water supplied to the unit that exceeds 12 grains
(205 mg/l) total hardness may reduce the life and perform-
ance of the water heater. Depending on the degree of hard-
ness, it is recommended that either a water pre-treatment
system or a water softener be installed and properly main-
tained.
Important: Heat cannot be applied to the water fittings on
the water heater as they may contain nonmetallic parts. If
solder connections are used, solder the pipe to the adapter
before attaching the adapter to the hot and cold water fit-
tings.
1. The water heater may have three water piping connec-
tion points. The top and front are 1-1/2” NPT and the
connections on the back of some heaters are 2” NPT.
When using front or back connections a combination
nipple inlet tube is required (top entry uses a dip tube).
Any one of the options listed in Table 5 may be used.
For availability contact 1-888-479-8324.
Note: Inlet and outlet piping connections cannot be mixed.
Damper in OPEN position
Damper wiring harness
Damper motor
Flue outlet reducer High
temperature
silicon sealant
Figure 6 Flue Outlet Reducer
Water Heater
Model Base #
Dip Tube
Inlet Tube
(Optional Front)
Inlet Tube
(Optional Back)
75-125 60238 60239 60239
80-199 60053 60057 60057
80-250 60053 60057 60057
100-199 71325 75085 75086
100-270 71325 75085 60023
75-300 60053 60057 60057
75-360 N/A 60194 60195
75-399 N/A 60194 60195
75-300NO
x
N/A 60194 60195
75-350NO
x N/A 60194 60195
Table 5 Dip Tube Usage
Figure 7 Water Piping Installation
Massachusetts:
Install a vacuum relief
in cold water line per
section 19MGL 142
Drain line 19mm
(3/4 in.) ID min.
Temperature and
Pressure Relief Valve
Pressure Reducing
Valve with Bypass
Cold Water
Supply to Fixtures
Main Water
Supply
In a closed system use a
Thermal Expansion Tank
Cold Water
Inlet Valve
Hot Water
Outlet
Unions
Floor Drain
Discharge line
152mm (6 in.)
max. above
drain
Metal drain
pan 45mm
(1-3/4 in.)
depth max.
Figure 5 Flue Damper Assembly
– 12 –
Bracket screws
Damper
motor
Drafthood
Drafthood
screws
Damper wiring
harness
Damper wiring
harness
Damper
motor
Damper in
OPEN position
Damper position
indicator
ECO wiring
harness