Domestic Hot Water Circuit; Boiler Wiring - COMBOMAX ULTRA 12-4.5 Installation Use And Care Manual

Ultra 12 to the relatively cold heating system
fluid (water) coming back from the radiant floor
(see figure 3).

3.6 DOMESTIC HOT WATER CIRCUIT

(Refer to figure 1 and 2 for component
identification and location).
3.6.1 Connecting the domestic hot water
piping
The COMBOMAX™ Ultra 12 boiler
WATER OUTLET and the COLD WATER INLET
connections are clearly marked. They are
located on the right side (when facing the boiler)
and are of ¾" NPT F type.
Use only clean copper or approved plastic pipe
for water connections.
regulations shall govern the exact type of
material to be used.
Insulate all pipes
especially in unheated areas.
A thermometer should be installed to indicate
the temperature of the water at or near the outlet
of the water heater.
3.6.2 Expansion tank on the cold water
supply line
Determine if a check valve, a back flow
preventer, a pressure-reducing valve, a water
meter or a water softener is present on the cold
water supply line.
Such items may create a closed system and
prevents the water as it is being heated from
expanding back into the cold water supply line.
Pressure can build up within the water heater,
causing the pressure relief valve to operate
during a heating cycle. This excessive operation
can cause premature failure of the relief valve
and possibly of the water heater itself.
Replacing the relief valve will not correct the
problem. One method of preventing pressure
build-up is to install an expansion tank on the
cold water supply
COMBOMAX™ Ultra 12 boiler unit and check
valve. Contact your installing contractor, water
supplier, local plumbing inspector or plumbing
supply house for assistance.
3.6.3 Domestic hot water pressure relief
valve
COMBOMAX™ Installation, use and care manual
HOT
Local codes
containing hot water,
line between
The COMBOMAX™ Ultra 12 boiler
factory equipped with a pressure relief valve
installed on the domestic hot water boiler outlet.
This pressure relief valve is set at 862 kPa (125
psi). Connect both the domestic hot water ( 862
kPa / 125 psi) and the tank heating system (207
kPa / 30 psi) pressure relief valves downward
toward safe location.
Relief valve outlet pipe diameter must not be of
smaller diameter than the relief valve outlet. The
oulet pipe end must be visible in order to
observe any relief incident and be protected
from freezing.
3.6.4 Thermostatically controlled mixing
valve (included)
The COMBOMAX™ Ultra 12 boiler
factory equipped
or
controlled mixing valve that reduce the risk of
scald injury by lowering the domestic hot water
temperature at the heat exchanger outlet, by
mixing cold fresh water to the hot water coming
out of the heat exchanger.
In order to adjust the mixing valve, hot water
must be consumed.

3.7 BOILER WIRING

3.7.1 Main power supply
The electrical wiring and grounding must
conform to local codes or, in their absence, to
the National Electrical Code. Local codes have
authority for wiring and electric breaker sizing. It
is the electrical technician responsibility to insure
that the installation meets the applicable codes
requirements.
On installation where a 120 Vac power is
required for a heating pump and other outboard
components,
COMBOMAX™ Ultra 12 must be a 120/240 Vac,
single phase, 60 Hz using 3 conductors (L1 –
L2 – N) and a ground wire..
On installation where no 120volts components
such a pump need to be powered by the
Combomax, Power supply could then be
the
supplied with only two conductors L1 L2 with a
ground wire.
Electrical current draw for the boiler being
installed is indicated on the boiler's name plate.
The electrical technician needs this information
in order to determine the proper electrical
,
(Revision Sept. 2013)
with a thermostatically
main power supply
Page
boiler is
boiler is
to the
8.