Cleaning The Filters; Removing Scale From The Dhw Circuit; Dismounting The Water-Water Heat Exchanger; Disassembling The Boiler Anode - Baxi Nuvola 3+ BS40 Operating And Installation Instructions

The DHW and CH filters are housed in special extractable cartridges. The CH cartridge is located on the CH return line
(figure 16F). To clean the filters, proceed as described below:
• switch off the boiler;
• shut the DHW inlet tap
• drain the water in the CH circuit by opening tap A in figure 16.
• remove the clip (1-F) from the filter as illustrated in the figure and take out the cartridge (2-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 - figure 16);
• 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.
WARNING
when replacing and/or cleaning the O-rings on the hydraulic assembly, only use Molykote 111 as a lubricant, not oil or grease.

31. REMOVING SCALE FROM THE DHW CIRCUIT

The cleaning of the DHW circuit can be carried out without removing the water-water exchanger from its housing if the
plate has been initially provided with the specific tap (on request) located on the DHW outlet.
To clean, proceed as follows:
• Turn off the DHW inlet tap
• Drain the DHW system by opening a hot water tap
• Turn off the DHW outlet tap
• Remove the clip 1E in figure 16
• Remove the filter (2E figure 16).
If the special tap is not supplied, dismount the water-water heat exchanger, as described in the next section, and clean
it separately.
To clean the exchanger and/or DHW circuit, use Cillit FFW-AL or Benckiser HF-AL.

32. DISMOUNTING THE WATER-WATER HEAT EXCHANGER

The stainless steel plate-type water-water heat exchanger can be easily disassembled with an M4 spanner by operating
as described below:
• drain the system, just the boiler if possible, through the drain tap;
• drain the DHW system;
• remove the two screws at the front securing the water-water heat exchanger and pull it out (figure 16B).

33. DISASSEMBLING THE BOILER ANODE

Check the state of the protective magnesium anode on
an annual basis
(before proceeding, empty the boiler circuit using the
relevant drain tap).
To disassemble the anode unit loosen the support nut (A)
using a 27 mm fixed wrench.

34. DISMANTLING, DISPOSAL AND RECYCLING

WARNING: only qualified technicians are authorised to service the device and system.
Before dismantling the appliance, make sure to have cut out the power supply, closed the gas inlet valve and secured all
the boiler and system connections.
Dispose of the appliance correctly according to the laws and regulations in force. The appliance and accessories cannot
be discarded along with normal household waste.
More than 90% of the materials that make up the appliance are recyclable.
INSTRUCTIONS FOR FITTERS

30. CLEANING THE FILTERS

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