Cleaning The Filters; Removing Scale From The Dhw Circuit; Dismounting The Water-Water Heat Exchanger - De Dietrich MS 24 BIC FF Notice D'installation, D'utilisation Et D'entretien

DRAINING THE STORAGE BOILER
Drain the water in the storage boiler as follows:
- close the water inlet tap;
- open a user tap;
- open the relative drain tap (Fig. 2-B);
- loosen the nut on the DHW outlet pipe at the bottom of the storage boiler.
The DHW and CH filters are housed in special extractable cartridges. The CH cartridge is located on the CH return line
(figure 15F). 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 15.
• 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 15);
• 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

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 15.
• Remove the filter (2E figure 15).
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 15B).
INSTALLATION INSTRUCTIONS

30. CLEANING THE FILTERS

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71.06199.02 - EN