25
NOTICE:
see Section “11.4 Bleeding and Releasing of Circulator
Shaft”.
− Begin venting all manual air vents in the hydronic piping system,
starting at the lowest first. It may be necessary to go back and add
water to the system to increase the pressure until the entire system
has been filled.
− Check the operation of the pressure relief valve by lifting the lever
from the seat. Purge air through this valve by keeping open until
only water comes out.
− Be sure boiler is in “OFF” mode. Open hot water tap(s) to remove
air from the DHW circuit. Keep open until only water exits the tap to
ensure the air is removed.
− Inspect the system for leaks, fixing any if found.
− After the air purging cycle the boiler is ready to operate.
If there is still air present during operation, repeat the air purging cycle.
9
WARNING:
Eliminate all system leaks. Continual fresh
makeup water will reduce boiler life. Minerals can build up in
the heat exchanger, reducing heat transfer, overheating heat
exchanger, and causing heat exchanger failure.
The system may have residual substances that could affect water
chemistry. After the system has been filled and leak tested, verify
water pH and chlorine/chloramines concentrations are acceptable
(see section ““7.13 Check/control water chemistry” page 24).
9
CAUTION:
It is important that you purge the system of air to
avoid damage to the boiler.
7 .17
Refill of the system
When the system needs to be refilled and an air purge is not
needed, perform the steps below:
− Put the boiler in OFF mode.
− Make sure the cold water inlet tap is open.
− Open the filling tap (
B
for combi boiler - external for heating only
boiler model).
− Check the pressure value on the screen: when the pressure
indicated by the sensor is between 15-21 psi (1-1.5 bar) close
the filling tap. To get the display screen to show the pressure
value refer to INFO MENU in s”11.10 Access to the INFO menu”
page 47
B
A
D
7 .18
Draining the heating circuit of the boiler
9
DANGER:
The system water temperature could be very hot,
be sure when opening the drain valve that the rubber pipe is
well attached. Water could spray from the front of the unit and
cause instant severe burns or death from scalds.
Before draining the system, switch off or disconnect the external
power supply to the boiler.
− Close the heating system’s valves.
− Manually loosen the system drain valve (
C
).
− Attach tube supplied in the loose parts bag to the outlet on the
system drain valve (
C
).
− Insert the open end of the tube into a bucket.
− Open drain valve (
C
) and allow water to drain out of system into
bucket.
− It is recommended to open the manual air vent (
D
) to release
any vacuum in the system to allow water to drain.
− To refill the system, close the vent and drain valves (
C
and
D
)
and see “7.17 Refill of the system” page 25 7.14.
C
7 .19
Emptying the domestic hot water system
Whenever there is risk of freezing, the domestic hot water system
must be emptied in the following way:
− turn off the main water supply tap
− turn on all the hot and cold water taps
− drain from the lowest points.
