Cola DOMUSFIRE C17 Installations-, Bedienungs- Und Wartungsanleitung Seite 47

2.8 Wiring diagram for zone system
Before installing the boiler in the home, check the type of heating system; if there are several zones, a special
electronic controller for multi-zone circuits, available as an optional, must be installed. This is to prevent overheating
of the unit due to possible simultaneous closing of the zone valves and consequent stopping of hot water delivery
flow.
2.9 Plumbing connections
The heating capacity of the unit must be previously established by calculating the building's heat requirement
according to current regulations, by contacting a specialised technician.
According to Italian Standard UNI 10412-2 (2009) and proper installation technique, a heating system must be
provided with all the adjustment, control and safety components to ensure proper and safe operation, as well as
shutoff and non-return valves to allow the boiler to be isolated from the system in case of maintenance and/or
checks.
There are two types of systems: CLOSED VESSEL system and OPEN VESSEL system. In the present case, both
types are compatible with our unit, provided all the adjustment, control and safety components required by the
current regulations on installation are installed.
The pellet boiler has an internal heating water circuit complete with circulating pump, safety valve, air vent,
temperature probes and pressure transducer.
If the heating system is managed in zones a multi-zone controller, available on request, must be installed.
In solid fuel boilers, to avoid the return of cold water in the heating chamber during the heating phase, it is advisable
to install an AUTOMATIC THERMOSTATIC VALVE (available on request) in the system to improve combustion
efficiency and boiler life and also reduce the condensation of fumes in the flueways, with less deposits and tars.
Before connecting the boiler to the water circuit, thoroughly clean all system pipes to remove any residuals or
machining residuals that could compromise the proper operation of the adjustment, control and safety components.
During boiler transport, the rings and respective seals in the water system may come loose and/or break,
causing water leaks during operation; therefore make sure to check the tightening of the circulating pump
and heating chamber connection rings and vent the residual air during water filling and after the first hours
of operation.
2.9.1 System water filling
After carrying out the plumbing connections, it is possible to FILL the unit and system:
- open all the air vent valves of the radiators - manifolds - boiler and system;
- open the water filling cock gradually, making sure the vent valves work properly;
- fill the system slowly, to allow proper and complete evacuation of the air from the vent, bringing the circuit under
pressure (for a closed vessel system from 1.1 to 1.5 bar);
- when finished, close the filling cock and make sure all vent valves have discharged the air from the system.
The creation of a heating system with installation of the boiler must comply with all the applicable
National, Regional, Provincial and Local regulations in the country where the system is installed.
2.9.2 System water characteristics
The chemical-physical characteristics of the system and replenishing water are important for the proper operation
and service life of the boiler; in fact, with the use of low quality water the most frequent problem is due to scale,
which causes a reduction in heat exchange and generates corrosion.
It is therefore advisable to check the water quality and, in the conditions listed below, provide for treatment:
- very hard water ( >20°f ),
- considerable amounts of replenishing water or subsequent fillings,
- systems of some complexity and size.
2.9.3 DHW system
To connect the boiler to a DHW system, it is advisable to see a qualified technician in order to
best optimise the plumbing connections and the performance of the entire system without compromising unit
functionality.
One of the following optionals must be requested for the connection to the DHW circuit:
- a DHW pump on the delivery manifold with respective connection pipes for placing inside the boiler.
- or a DHW pump, plate heat exchanger and connection pipes for placing inside the boiler.
3-way valve
- or a for installing outside the boiler.
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DOMUSFIRE C17-C24