29
R
To measure combustion performance and hygiene levels of combustion products, the forced draught
boiler models are equipped with two test points on the tapered coupling specifically designed for
this purpose.
One of the two test points is connected to the exhaust flue duct to allow measurements of the com-
bustion products hygienic standards and combustion efficiency.
The second test point is connected to the comburant air inlet duct to check possible combustion
products circulation in case of coaxial ducts.
The exhaust flue duct test point allows measurements of the following:
• combustion products temperature;
• concentration of oxygen (O
2
) or, alternatively, of carbon dioxyde (CO
2
);
• concentration of carbon monoxyde (CO).
The comburant air temperature must be measured at the test point connected to the air inlet duct.
18. Check of combustion
parameters
Figure 16
To facilitate measurement of the combustion efficiency and improve the cleanliness of the production
products, the flue-sweeper function can be activated by proceeding as described below:
1) press the (2-3) together until the pointer “ ” appears on the display alongside the symbol
(about 3 seconds but no more than 6 seconds). In these conditions, the boiler operates at the ma-
ximum heat output set for central heating.
2) press either of the buttons to exit the function
19. Activating the
chimney-sweeper function
020429_0300
gasket
combustion air
flue gas
020429_0200
Figure 17
To ensure the boiler operates at peak efficiency, the following checks must be performed every
year:
• check on the appearance and tightness of the gas and combustion circuit gaskets;
• check on the condition and position of the ignition and flame sensing electrodes (see section
17);
• check on the condition of the burner and its fixing to the aluminium flange;
• check for any dirt in the combustion chamber. Use a vacuum-cleaner for this cleaning opera-
tion,
• check if the sifon is dirty;
• check that the gas valve is calibrated correctly (see section 14);
• check on the central heating system pressure.
20. Annual service
