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PART NO. 100266523
CIRCULATOR PUMP
A circulator pump is not supplied. Use only a bronze body
model rated for 110/120 volts, 60Hz. Install in accordance
with the pump manufacturer’s instructions using standard
plumbing practices. Size the circulator pump taking into
account the pressure loss through the tankless coil boiler or
instantaneous water heater as well as pressure losses through
the connecting pipes that are part of the circulating loop.
SIZING THE HOT WATER SYSTEM
Temperature of the system is controlled by the temperature
set point of the instantaneous water heater or boiler coil.
Given the limited storage capacity of the storage tank and the
maximum output of the tankless coil boiler or instantaneous
water heater, large hot water draws signi
fi
cantly exceeding
the circulating loop
fl
ow rate may lead to a reduction in
temperature of hot water delivered.
PLUMBING CONNECTIONS
The water heating source piping and components
connected to the tank must be suitable for potable water
use. TOXIC chemicals such as used for boiler treatment
must not be introduced into the tank.
Toxic Chemical Hazard
WARNING
For a temperature controlled instantaneous water heater it is
recommended to install the plumbing as shown in Figure 2.
It is also recommended to set-up and control the IWH outlet
temperature to be at least 11°C (20°F) above tank thermostat
temperature. The recommended plumbing installation for a
tankless coil boiler is shown in Figure 3. In this case, because
the tankless coil boiler is able to control only the differential
between inlet and outlet temperature, the cold water entering
the tankless coil boiler must be tempered with hot water from
the storage tank. As there is a large variety of heat sources
and control systems, please contact your local distributor for
the plumbing system to identify the solution that best suits
your application.
Do not apply heat directly to tank fittings when making
sweat connections. They contain non-metallic material.
Property Damage Hazard
CAUTION
FROM IWH
TO IWH &
CIRCULATOR
PUMP
T&P VALVE
HOT
WATER
PIPE INSULATION
COLD IN
THERMOSTAT
WITH HIGH-
LIMIT SWITCH
DRAIN VALVE
FLOOR DRAIN
DRAIN PAN
PRESENT ON
SOME MODELS
ONLY (NOT USED)
Figure 1. Main Parts and Features for Connection to a
Temperature Controlled IWH
1. Ensure the storage tank is level before starting installation.
2. Install a circulation loop as shown using 19mm (3/4 in.)
copper piping.
3. If the heating source is a tankless coil boiler go to Step 4.
If a temperature controlled IWH is used as a heat source,
install the combination inlet/drain valve in one “arm” of a
tee connected to the lower storage tank fitting. Connect
the cold water supply piping to the inlet of the combination
inlet/drain valve. Connect the other “arm” of this tee to
the IWH inlet line and place the circulating pump in this
line. Connect the IWH outlet to the upper storage tank
side fitting (see Figure 2). Proceed to Step 5.
4.
For a tankless coil boiler install the combination inlet/drain
valve in the lower storage tank fitting. Connect the inlet
of a combination inlet/drain valve to the hot outlet of the
tankless coil boiler. In this instance the “leg” of a tee should
connect to the cold water supply line, one “arm” connects
to the circulator pump and the other “arm” to the inlet of
the tankless coil boiler. The circulator pump connects to
the upper side fitting of storage tank (see Figure 3).
