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3.3. Filling the system
After having performed all connections of the system, fill the heating circuit.
This operation must be carried out with caution according to the following steps:
- open the outlet valves of the radiators and make sure the automatic valve of the boiler works properly;
- open gradually the filling tap (fig. 2) to make sure the automatic air relief valves installed on the system run smoothly;
- close the radiators relief valves as soon as water comes out;
- check by means on the boiler pressure gauge to make sure the pressure has reached 1÷1.3 bar;
- close the filling tap and then vent the air through the venting valves of the radiators;
- after having started up the boiler and brought the system to the temperature set, stop the pump operation and repeat the air bleeding;
- allow the system to cool and bring the water pressure to 1÷1.3 bar.
WARNING
The UNI CTI 8065/89 standard "Water treatment in domestic heating systems" determines and defines the chemical and physical
features the waters used in thermal plants for civil use must have: "... in order to optimize the performance and safety and pre-
serve them over time, to ensure lasting regular operation also of the auxiliary equipment and to minimize the energy consumption
thus integrating laws and regulations;...".
This regulation must be complied with by law (Law 5/3/90 n.46, Presidential Decree no.412 28/8/93).
Therefore, use specific products suitable for systems made from multiple metals (see paragraph 3.2.4).
CAUTION
The pressure sensor does not send the electric consent for burner ignition when the pressure is lower than 0.5 bar.
The water pressure in the heating system must not be lower than 1 bar; otherwise, act on the filling tap fitted on the boiler (fig. 2).
The operation must be performed when the system has cooled. The digital pressure gauge allows reading the pressure of the
heating circuit.
3.4. Starting up the boiler
3.4.1. Preliminary checks
Prior to starting-up the boiler check that:
- the fumes exhaust pipe and the terminal part are installed in accordance with instructions:
when the boiler is switched on, no com-
bustion products leaks are detected
;
- the boiler supply voltage is 230 V ~ 50 Hz;
- the system is properly filled with water (pressure gauge 1÷1.3 bar);
- all interception valves (if provided) of the system pipes are open;
- the gas network matches the boiler calibration: otherwise, perform the conversion of the boiler to the gas type use available (see section
- the gas supply valve is open;
- no gas leaks are detected;
- the main power switch upstream the boiler is enabled;
- the 3 bar safety valve is not blocked;
- no water leaks are detected;
- the condensate draining siphon, fitted on the boiler, drains correctly the condensate and is not clogged.
3.4.2. Start-up and shut-down
For the switching on and off of the boiler follow the "
Instructions for the user
".
