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5790 733 - 07
Vitocrossal 300 CA3 Series 2.5 to 6.0 Installation/Service
Installation
Initial System Fill
Treatment of boiler feed water should be considered in
areas of known problems, such as high mineral content
and hardness. In areas where freezing might occur, an
antifreeze may be added to the system water to protect
the system (maximum mix ratio - 50% / 50%). Please
adhere to the specifications given by the antifreeze
manufacturer for hydronic heating systems.
Please observe that an antifreeze/water mixture may
require a backflow preventer within the automatic water
feed and influence components such as diaphragm
expansion tanks, radiation etc. A 40% antifreeze content
will provide freeze-up protection to -31°F (-25°C).
The heating system may also contain components which
may be negatively affected by antifreeze. Check entire
system frequently when filled with antifreeze. Read boiler
service instructions for further information on water
quality.
The Vitocrossal 300, CA3 boiler is only suitable for closed
hot water heating systems with pumps.
It is strongly recommended to install boiler isolation valves
and above these isolation valves, drain valves in the system
supply and return. With this installed, any maintenance
work on the boiler or heating system, will not require
draining the entire system.
When the boiler is utilized to supply heat to an indirectly
heated domestic hot water tank, it is necessary that the
heating loops (without a mixing valve) are equipped with
flow check valves on the discharge side of the pumps to
avoid reverse flow.
The pressure relief valve must be attached to the top of
the boiler or the safety supply of the boiler (see page 15).
No valve, shut-off device or obstruction of any kind and
no construction must be used between boiler and relief
valve or on the discharge side of the pressure relief valve.
The discharge side of the pressure relief valve must continue
in the same size as the outlet horizontally over the side of the
boiler, and then vertically downwards to end approximately
1 ft. (300 mm) above the floor, and piped as close to a floor
drain as possible. Do not install this discharge pipe to the
outdoors or any area where freezing might occur or the
discharge pipe could endanger life and equipment.
IMPORTANT
CAUTION
Before the heating boiler is installed and piped into an
existing system, the heating system itself must be
properly flushed to remove dirt and system sludge.
Accumulations in old heating systems will tend to settle
in the boiler and can lead to deposits which can cause
hot spots, noise and water-side corrosion. For damages
resulting from those kinds of impurities, the warranty
will be null and void.
IMPORTANT
Cold water fill pressure must equal expansion tank pressure.
Ensure that there is no leak on any of the connections
which are covered by the insulation.
The boiler should be filled and properly bled of air and
the cold water fill pressure should not exceed 18-20 psig.
All openings, as well as pipe connections on the boiler,
should be observed for possible leaks. Once all
connections are tight, the insulation can be mounted.
WARNING
Fill only suitable water in boiler. Unsuitable water
quality may damage boiler.
IMPORTANT
Only use antifreeze specific for hydronic heating
systems. Do not use automotive glycol!
Secure the discharge piping from the pressure relief valve
with the appropriate hangers or brackets.
IMPORTANT
