40
3.25 - Filling the
heating system
Fill the heating system using only
cold water from the main water
supply; proceed as follows:
Check that the system has been
filled and purged.
The indicator on the pressure
gauge “6” (see fig.48), should read
between 15 and 25 psi (1 and 1.7
bar).
If the pressure gauge reads below
15 psi (1 bar), open the automatic
feed using the fast fill feature and
allow the system to fill, untill the
pressure gauge reads 25 psi (1.7
bar)
To properly purge the heating
system of air it is imperative that
these basic instructions be
followed.
The automatic feed should have a
fast fill feature. There must be an
isolation valve installed so that
when it is closed it will direct the
incoming water flow through the
system and heater in the normal
flow pattern and out a drain cock
installed at the end of the loop.
a) Attach a hose to the heating
drain cock and run the hose to a
suitable drain.
b) Open heating drain cock.
c) Open the automatic feed using
the fast fill feature and allow the
system to fill purge. On multi-zone
systems, each zone must be
purged separately with the other
zones shut off.
unscrew the air vent cap located in
top of heater (see figure 1 item 3).
3.26 - Ignition
Open the gas cock.
Switch on the electrical on/off
switch to the heater.
Rotate selector “4” (see fig. 48) to
position “C” (Domestic hot water
plus heating).
The circulation pump starts only
when the heater temperature
exceeds 140°F (60°C) and when
the room thermostat calls for
heating.
If the pump indicator “C” (see fig.
3 - INSTALLATION
45) is illuminated but the pump is
not running, this might indicate that
the pump is frozen in place, remove
the screw cap on the pump and
rotate with a screwdriver to try
releasing it.
If the pump indicator is illuminated
but the radiators fail to heat up
adequately, this might be an
indication that there is air in the
system. Re-purge the system until
air is eliminated.
3.27 - Regulating
the domestic hot
water
The heater temperature control
knob is adjusted to its lowest
temperature position when shipped
from the factory. Prior to starting
the heater, it should be adjusted to
a minimum starting point of 140°F
(60°C) as shown on the heater’s
temperature control. After installing
the heater, it is necessary to
regulate the flow rate of the
domestic hot water so as to give a
75°F (42°C) rise. For this function,
you need to use a flow meter and a
thermometer. Place the flow meter,
under a hot water faucet, closest to
the heater and open the faucet until
water temperature is stabilized.
The difference between cold and
hot water should be approximately
75°F (42°C). Increase or decrease
the water flow by regulating the
incoming cold water to the heater
with the DHW flow restrictor (see
figure 23, items 15).
When water temperature
requirements for heating are higher
than the temperature of the
domestic hot water, (120° F (49°C))
you must temper the domestic hot
water output to reduce the potential
hazard of scalding.
It is
IMPARATIVE that a mixing valve
be installed external of the
heater to further regulate the
temerature of the domestic hot
water.
