Filling The System; Turning Off The Boiler; Prolonged Shutdown. Frost Protection; Gas Conversion - Baxi Nuvola 3+ BS40 Operating And Installation Instructions

IMPORTANT:
Regularly check that the pressure displayed on the pressure gauge is 0.7 - 1.5 bar, with the boiler cold.
In case of overpressure, open the boiler drain valve. If pressure is lower, open the boiler filling tap (figure 3).
Open the tap very slowly in order to vent the air.
During this operation, the boiler must be "OFF" (press
In case pressure drops occur frequently, have the boiler checked by an authorised Service Engineer.
A: System emptying tap
B: Boiler emptying tap
Figure 3
C: System filling tap
The boiler is fitted with a hydraulic pressure gauge which prevents the boiler from working if the pump is blocked or if
there is no water.
To turn off the boiler, disconnect the electric power supply. With the gas boiler in the "OFF" mode (section 3.2), the electric
circuits remain powered and the frost protection function is enabled (section 7).

7. PROLONGED SHUTDOWN. FROST PROTECTION

Do not drain the whole system as filling up with water again causes unnecessary and harmful scale to build up inside the
boiler and the heating elements. If the boiler is not used during winter and is therefore exposed to the danger of frost, add
some specific anti-freeze to the water in the system (e.g.: propylene glycol coupled with corrosion and scale inhibitors).
The electronic boiler management system includes a "frost protection" function for the heating system which, when delivery
temperature falls below 5°C, operates the burner until a delivery temperature of 30°C is reached.
The frost protection function is enabled if:
* the boiler is electrically powered;
* the gas tap is open;
* the system is at the correct pressure;
* the boiler is not blocked.
The boilers can operate both on natural gas and LPG.
Any gas change must be effected by a Qualifi ed Service Engineer.
INSTRUCTIONS FOR USERS

5. FILLING THE SYSTEM

- figure 1).
A B

6. TURNING OFF THE BOILER

8. GAS CONVERSION

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C
7217402.01 - en