John Wood Atmospheric Gas (ENERGY STAR) - NEW - Manuel (Page 14)

14
Figures 10-12 are examples of vent pipe system
installations and may or may not be typical for your
specific application. Consult the “Natural Gas and Propane
Installation Code,” CAN/CSA B149.1-current edition and
the guidelines set forth by prevailing local codes.
Vent Size Verification
It is possible that the existing venting system was sized
through a common vent for a previous installation. Such
an arrangement is appropriate for venting two appliances
(such as the original water heater and a standard vent
furnace). If this is true and the second appliance has been
removed from the existing venting system (such as when
the furnace has been upgraded to a power vent type), the
venting system is now supplying only one appliance. This
condition is commonly referred to as “orphaning.” In such
cases, the venting system must be properly resized
for a single appliance.
Therefore, it is important to verify the size of the existing
venting system. Improper sizing can cause a number
of undesirable and potentially unsafe results including
spillage of the products of combustion into the room, poor
combustion, excessive condensation, pilot outage, or
delayed ignition. The vent pipe must not be obstructed so
as to prevent the removal of exhaust gases to the outside
atmosphere.
specified under Closed System/Thermal Expansion.
5. Install a shut-off valve in the cold water inlet line. It
should be located close to the water heater and be
easily accessible. Know the location of this valve and
how to shut off the water to the heater.
6. A temperature and pressure relief valve must be
installed in the opening marked “Temperature and
Pressure (T & P) Relief Valve” on the water heater.
A discharge line must be added to the opening of
the T&P Relief Valve. Follow the instructions under
Temperature and Pressure Relief Valve.
7. After piping has been properly connected to the water
heater, remove the aerator at the nearest hot water
faucet. Open the hot water faucet and allow the tank
to completely fill with water. To purge the lines of
any excess air, keep the hot water faucet open for
3 minutes after a constant flow of water is obtained.
Close the faucet and check all connections for leaks.
SUITABLE DRAIN
HOT WATER
OUTLET COLD WATER
INLET
PRESSURE REDUCING VALVE
WITH BYPASS
COLD WATER SUPPLY TO FIXTURES
COLD WATER INLET VALVE
(SHUT-OFF VALVE)
IN A CLOSED SYSTEM USE A
THERMAL EXPANSION TANK
TEMPERATURE AND PRESSURE (T&P)
RELIEF VALVE (OPTIONAL TOP T&P
RELIEF VALVE NOT SHOWN)
DRAIN LINE
3/4” ID
MINIMUM
METAL
DRAIN PAN
1” MINIMUM
12” (300 mm)
MAXIMUM AIR GAP
DISCHARGE PIPE
(DO NOT CAP OR PLUG)
FIGURE 13.
COLD
WATER
INLET
HOT
WATER
OUTLET
TEMPERED WATER
TO FIXTURES
MIXING VALVE
(SET TO 120°F)
FOLLOW THE MIXING
VALVE MANUFACTURER’S
INSTRUCTIONS
UNTEMPERED
HOT WATER
FIGURE 14.
Please note the following:
•
The system should be installed only with piping that is
suitable for potable (drinkable) water such as copper,
CPVC, or polybutylene. This water heater must not be
installed using iron piping or PVC water piping.
WATER SYSTEM PIPING
Piping Installation
Piping, fittings, and valves should be installed according
to the installation drawing (Figure 16). If the indoor
installation area is subject to freezing temperatures, the
water piping must be protected by insulation.
The water supply pressure should not exceed 80 psi. If this
occurs, a pressure reducing valve with a bypass should be
installed in the cold water inlet line. This should be placed
on the supply to the entire house in order to maintain
equal hot and cold water pressures.
IMPORTANT: Heat cannot be applied to the water fittings
on the 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
fittings.
IMPORTANT: Always use a good grade of joint compound
and be certain that all fittings are drawn up tight.
1. Install the water piping and fittings as shown in Figure
13. Connect the cold water supply (3/4” NPT) to the
cold water inlet fitting. Connect the hot water supply
(3/4” NPT) to the hot water outlet fitting.
IMPORTANT: Some models may contain energy saving
heat traps to prevent the circulation of hot water within the
pipes. Do not remove the inserts within the heat traps.
2. The installation of unions in both the hot and cold water
supply lines is recommended for ease of removing the
water heater for service or replacement.
3. The manufacturer of this water heater recommends
installing a mixing valve or an anti-scald device in the
domestic hot water line as shown in Figure 14. These
valves reduce the point-of-use temperature of the
water by mixing cold and hot water and are readily
available for use.
4. If installing the water heater in a closed water system,
install an expansion tank in the cold water line as