FireBird Enviromax Popular C20 Technical Manual page 26

3 3.3 - DOMESTIC HEATING & HOT WATER
METHOD B
N.B. Remember also to check air fill pressure of
Expansion Vessel when system is cold
using standard tyre gauge connected to
Schrader air valve on vessel.
NOTE: There shall be no direct connection to the
mains, even with the use of a non-return
valve without the permission of Local
Water Authority.
* It is recommended that an inhibitor be added
at the time of final fill to protect the System
from corrosion. Ensure that this is carried out
in accordance with inhibitor manufacturers
instructions. Installer should ensure that
inhibitor used is suitable and that it will have
no adverse effect on Expansion Vessels
diaphragms or any other part or component
of the system.
COMMISSIONING
* Before proceeding to filling, ensure that electric-
ity supply is switched off at mains to avoid any
possibility of time switch operating and passing
power to appliance prior to filling.
Filling and Testing
Check that all connections, especially compression
joints, are fully tightened. Re-check and ensure that
pressure vessel air charge is correct, then fill system
with water via filling system used. Turn off water
supply before system pressure reaches safety valve
operation point of 3 bar. (Say 2 to 2.5 bar).Vent system
via all manual air vents including circulating pumps,
boiler, radiators, system high points. etc. Check that dust
caps are loosened on auto air vents, keep constant
check on system pressure gauge (fitted to control
panel). If pressure has dropped re-admit water to above
pressure. Ensure all appropriate boiler and system
valves are open.
With water supply turned off, thoroughly flush out
boiler and system to remove all foreign matter before
allowing boiler and pumps to operate. If in doubt drain
system and repeat above procedure. At this stage
flushing-out water should be clean and clear of all
foreign matter.
Refill the system and again vent at all points as
described above. Examine the complete system for
water leaks having pressurised it to 1 - 2.5 bar. Correct
any leaks, then check operation of safety valve by
admitting further water until this valve operates. This
should occur when system pressure rises to between
2.7 and 3.3 bar.When satisfied with valve operation, and
with mains water still turned off, draw off sufficient
water until initial system design fill pressure (P i ). (cold
fill) is established (0.5 - 1 bar - as calculated for system).
Remember that initial cold fill pressure can only be
checked when system water has properly cooled down.
Check that final operating pressure (P f ) is under 2.5
bar with all radiators turned on and up to highest
working temperature. Should system operating
pressure exceed this, check:
1. That initial cold fill pressure is correct and , if
additional expansion vessel is fitted, that
pressure is equal in each vessel.
2. That expansion vessels are sized correctly.
Special attention should be given to existing
heating systems where Firebird Combi C boiler has
replaced an existing unit. Extra effort should be
made to ensure that all original pipe work and
radiators are repeatedly flushed. If possible use a
proprietary cleansing agent suitable for system as
loosened scale and foreign matter can seriously
reduce domestic hot water performance and pump
efficiency.
Use corrosion inhibitor of suitable type.
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Firebird Enviromax Condensing Range