Cleaning The Filters; Removing Scale From The Dhw Circuit - DeDietrich MS 24 MI FF 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) while the DHW cartridge is on the cold water input (figure 16E). 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-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 - 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.
• to change the DHW NTC sensor, see figure 16D.
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 DHW circuit can be cleaned without removing the water-water heat exchanger if the assembly is fitted with the special
tap (available on request) located on the DHW outlet. To clean, proceed as follows:
• Close the DHW inlet tap;
• Drain the DHW system by opening a hot water tap;
• Close the DHW outlet tap;
• Remove the clip 1E in figure 16;
• Remove the filter (2E figure 16);
• to change the DHW NTC sensor, see figure 16D.
If the special tap is not supplied, dismount the water-water heat exchanger, as described in the next section, and clean it
separately. Remove the scale from the seat and relative NTC sensor fitted on the DHW circuit (figure 16D).
To clean the exchanger and/or DHW circuit, use Cillit FFW-AL or Benckiser HF-AL.
INSTALLATION INSTRUCTIONS

30. CLEANING THE FILTERS

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71.03982.03 - EN