18. ANNUAL SERVICING
If the boiler was operating, wait for the combustion chamber and pipes to cool down.
Before commencing any maintenance operations, make sure the boiler is disconnected from the power supply. Afterwards,
move the knobs and/or operating parameters of the boiler to their original positions.
Do not clean the boiler with abrasive, aggressive and/or easily flammable substances (such as petrol, acetone, etc.).
To optimise boiler efficiency, carry out the following annual controls:
• Check the appearance and airtightness of the gaskets of the gas and combustion circuits;
• Check the state and correct position of the ignition and flame-sensing electrodes;
• Check the state of the burner and make sure it is firmly fixed;
• Check for any impurities inside the combustion chamber. Use a vacuum cleaner to do this;
• Check the gas valve is correctly calibrated;
• Check the pressure of the heating system;
• Check the pressure of the expansion vessel;
• Check the fan works correctly;
• Make sure the flue and air ducts are unobstructed;
18.1 HYDRAULIC UNIT
For special areas, where the water is harder than 20 °F (1 °F = 10 mg calcium carbonate per litre of water), install a polyphosphate
dispenser or an equivalent treatment system, compliant with current regulations.
18.2 POSITIONING THE ELECTRODE
The electrode must completely cross the width (L) of the burner element.
18.3 CLEANING THE FILTERS
The DHW and CH filters are housed inside removable cartridges (see figure in annex "SECTION" F at the end of this manual).
The CH cartridge is located on the CH return line (F) while the DHW cartridge is on the cold water inlet (E). To clean the filters,
proceed as described below:
• switch off the boiler;
• shut the DHW inlet valve;
• drain the water in the CH circuit by opening valve (A);
• remove the clip (1-E/F) from the filter as illustrated in the figure and take out the cartridge (2-E/F) containing the filter, taking
care not to apply excessive force;
• to extract the heating filter cartridge, first remove the 3-way valve motor (1-2G);
• eliminate any impurities and deposits from the filter;
• reposition the filter in the cartridge and put it back into its housing, securing it with the clip.
• The NTC DHW sensor is positioned in point (D).
when replacing and/or cleaning the O-rings on the hydraulic assembly, only use Molykote 111 as a lubricant, not oil or
grease.
7110102.03 (1-06/13)
L
42
CG_2399