COMBOMAX
MC
Electric boiler Set-up, use and care guide
(revised Oct 2015)
, Page
10.
Section 4 : Operation
Before operating this water heater, be sure to
read and follow these instructions, as well as
the warnings printed in this manual. Failure
to do so can result in unsafe operation of the
water heater resulting in property damage,
bodily injury, or death. Should you have any
problems reading, following or difficulty in
understanding the instructions in this
manual, STOP, and get help from a qualified
person.
Do not turn on the water heater unless it is
filled with water. Do not turn on water heater
if cold water supply shut-off valve is closed.
Once the plumbing and electrical connections
are completed, your COMBOMAX
MC
unit is
ready for automatic operation.
4.1 FILLING THE TANK
Open the outlet valve (in a zone valve system,
manually open the zone valves).
Open the boiler inlet valve. Bleed the air from
the boiler tank by opening the safety valve atop
the boiler while you are filling the tank.
Leave all valves open. Reset the zone valves to
automatic operation. Check for leaks and repair
if necessary.
Bleed the air from all zones if required. Check
the boiler pressure gauge. A pressure reading
between 15 and 20 psi is normal for most
installations.
4.2 FILLING THE HEATING COIL
Make sure all drain cocks are closed.
Open the nearest domestic hot water tap as well
as any control valve on the water heater outlet
(the copper tube atop the boiler).
Open the cold water inlet valve on the heater
inlet tube. (the copper tube on the left side of the
unit).
Close the domestic hot water tap as soon as
water flows out of it. Fix any leaks
Open all other hot water taps fed by this heating
coil to bleed the air trapped behind them.
4.3 ADJUSTING THE AQUASTATS
Once all air has been bled from the system and
all components (valves, bleeders, controls) have
been properly adjusted, the boiler can be put
into operation. Never operate the boiler before
these adjustments are complete.
Bear in mind safety and energy-saving
considerations when adjusting the boiler water
temperature with the aquastats. It is most
energy-efficient to set them as low as possible,
in a manner consistent with your heating needs.
However, a minimum temperature of 160°F is
recommended for domestic hot water
production.
Each aquastat controls a boiler stage (each
element has its own aquastat). Adjust the setting
of each aquastat by turning the dial scaled in
degrees Celsius and Fahrenheit. See figure 10
for aquastat identification.
Set the first aquastat to the highest outlet
temperature required by the heating system and
the domestic hot water. Thermo 2000 inc.
recommends a setting around 180F to get the
maximum capacity.
Adjust the second aquastat around 5F lower
than the first one and
p
roceed in a similar
manner for the 3rd and 4th aquastats, Thus, the
number of elements in operation will increase as
the boiler temperature will decrease.
The domestic hot water priority aquastat should
be adjusted to a setting around 10
o
F below that
of the last stage or 4
th
aquastat.
Note: The maximum setting for the boiler outlet
temperature is 190°F.
4.4 STARTUP PROCEDURE
1. Fill tank and coil as described in
sections 4.1 and 4.2.
2. Adjust temperature levels as described
in section 4.3
3. Set building thermostat setting(s) below
room temperature.
4. Activate boiler main breakers.
SAFETY PRECAUTIONS
!
