Checking The Function Of All Safety Equipment; Checking The Expansion Vessel And System Pressure - Viessmann VITOCROSSAL 300 Service Instructions Manual

Further details of the individual steps

Checking the function of all safety equipment

Check the safety valves, the water
level and pressure limiters in
accordance with manufacturer's
instructions.
Checking the expansion vessel and the system pressure
Note the manufacturer's instructions. Carry out this test on a cold system.
Expansion vessels with pump or compressor control
¨ In heating systems where the pressure is maintained automatically
(especially for systems with pump control) and/or de-gassing systems
(operating acc. to the pressure reduction method for de-gassing), we
recommend the installation of a diaphragm expansion vessel (MAG) as
individual boiler protection.
A common expansion vessel can be used for any multi-boiler systems.
The diaphragm expansion vessel must be able to hold the heating water
expansion volume inside the boiler, and provide a capacity of at least
35 litres.
This diaphragm expansion vessel reduces the frequency and severity of
pressure fluctuations; the service life of the pressure pump is improved
and therefore the operational reliability and service life of system
components is increased.
Damage to the boiler or other system components may result if these
recommendations are not followed.
Carry out the checks in accordance
with manufacturer's instructions.
Limit pressure fluctuations to the
lowest possible differential.
Cyclical pressure fluctuations and
Initial start-up, inspection and maintenance
(cont.)
greater pressure differentials
indicate a system fault. Immediately
remedy such faults, otherwise other
heating system components may
become faulty.
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