PENSOTTI PCI 18, Instruction Manual

Page: 38 / 70

INSTALLATION INSTRUCTIONS
34
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;
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;
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 14 psi (1 bar) and that the code H2O does NOT appear on the control panel display (see 2.7
section ‘Control Panel’);
If, after the above operations, there is a reduction in the pressure, re-open the filling tap R until the pressure gauge
reads 14 psi (1 bar) and that the code H2O disappears on the control panel display;
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 boiler 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).
R M
AIR VENT VALVE PLUG
PUMP PLUG
PUMP
AIR VENT VALVE
Fig. 2
Fig.
1