Installation instructions
19
Attention!
Before connecting the boiler to the heating
system, thoroughly clean the piping with an
appropriate product in order to eliminate
metallic residue from processing and welding,
oil and grease which could be present and
which, reaching the boiler, could alter its
functioning.
Do not use solvents to wash the system as
they could damage the system and/or its
components.
Failure to comply with the instructions of the
following manual can cause damage to
persons, animals and objects for which the
manufacturer cannot be held responsible.
Attention!
Make sure that there are no mechanical
tension points while connecting the pipes
to avoid the risk of leakage!
Heating flow and return pipes must be connected to the boiler
at the respective fittings as indicated on pages 8, 9 and 10.
For the dimensioning of the heating circuit pipes, you must
take into account pressure drops caused by radiators,
thermostatic valves, radiator stopping valves and by the
configuration of the system.
The laying of the pipes must be designed taking every necessary
precaution to avoid air pockets and to facilitate continuous
degassing of the system.
Make sure that the pipes of the water and heating
system are not used as earthing electrodes of
the electric or telephone system.
There absolutely not suitable for this use.
Serious damage could result for the piping, boiler and radiators
in a short amount of time.
Heating system safety valve drain
Provide a drain pipe with a funnel and a siphon leading to an
appropriate drainage at the heating safety valve. This drainage
must be controlled on sight.
Attention!
If this precaution is not taken, triggering of
the safety valve can cause damage to persons,
animals and objects for which the
manufacturer cannot be held responsible.
Connection of expansion vessel
XC-K boilers are suitable for operating with forced
water circulation both with the expansion vessel
opened or closed.
An expansion vessel is always necessary to
compensate the increase in water volume due
to heating.
The connection pipes of the expansion vessel will start from
the T4 attachment (see DIMENSIONS TABLES) and must have
no shut-off valve.
Connection of filling/draining tap
A specific tap can be connected to the T5 attachment at the
rear of the boiler for filling and draining.
3.10 - CONNECTING BOILER TO SYSTEM
3.11 - FILLING THE SYSTEM
Attention!
Do not mix the heating water with incorrect
concentrations of antifreeze or anti-corrosion
substances! This could damage the gaskets
and cause noise during operation.
Unical will not be held liable for damage to
persons, animals or objects due to failure
to comply with the instruction above.
When all system connections have been completed, the circuit
can be filled.
This operation must be performed carefully, respecting the
following phases:
-
open the radiator air release valves.
-
open the filling tap gradually, making sure that the automatic
air release valves installed on the system work properly.
-
close the radiator air release valves as soon as water
comes out.
-
check the pressure gauge until pressure reaches
approximately 1 bar.
-
close the filling tap and bleed air once again through the
radiator air release valves.
-
make sure that all the connections are watertight.
-
after commissioning the boiler and bringing the system to
the operating temperature, stop the pumps and repeat the
air bleed operations.
-
let the system cool off and, if necessary, return the water
pressure to 1 bar.
