PENSOTTI PCC 34-H, Instruction Manual

Page: 41 / 72

INSTALLATION INSTRUCTIONS
38
4.2 Filling the system
Check the properties of the water supply and install the
appropriate treatment devices if the mains water has a
hardness rating more than 7 grains/gal. (120 ppm) in order to
prevent scaling and eventual damage to the D.H.W heat
exchanger.
A pressure reducing valve and backflow preventer must be
installed.
Use only clean tap water to fill the system.
Once the water pipes have been connected, close the gas feed valve
and fill the system as follows:
Check that the circulation pump runs freely;
Check that the plug of the air vent valve has been slackened slightly
to allow air to escape from the system (fig.1);
Purge all air from primary heat exchanger using the manual air vent.
Open the main domestic water supply valve;
Open the filling tap R (fig. 2);
Unscrew the plug on the pump to remove any trapped air, check that
the pump is free then re-tighten it when water starts to flow out (fig.1);
Before switching on the boiler, purge air completely from the air
vent valve positioned on the top of the condensing exchanger
(fig. 3)
Open the air vents on the radiators and monitor the air evacuation
process. When water starts to flow out of the radiators, close the air
vents;
Use the pressure gauge M (fig. 2) to check that the system pressure
reaches the middle of the green section (14.5 psi = 1 bar) and that
the code H2O does NOT appear on the control panel display (see 2.7
section ‘Control Panel’);
On completion, make sure that the filling tap R is perfectly
closed.
Emptying the central heating system
Whenever it is necessary to empty the system, proceed as follows:
turn off the main power supply switch;
wait for the appliance to cool down;
turn the system drain tap RS (see fig. 2) and use a container to collect
the water that runs out;
Emptying the domestic hot water system
Whenever there is danger of freezing or any other occurrence, the hot
water system could be emptied in the following way:
Shut off the water at the mains;
Open all hot and cold water taps;
Empty from the lowest point (where possible).
3
2
1
4
R M
GREEN SECTION
14.5 psi = 1 bar
7.2 psi = 0.5 bar
21.5 psi = 1.5 bar
43 psi = 3 bar
PUMP PLUG
PUMP
AIR VENT VALVE PLUG