How To Purge The Dhw System From Limestone Deposits; How To Disassemble The Dhw Heat Exchanger; Cleaning The Cold Water Filter - Baxi Luna 3 Comfort Series Installation And Servicing Instructions

15. how to purge the dhw system from limestone deposits

(not fitted on 1.310 Fi model)
To clean the DHW system it is not necessary to remove the DHW heat exchanger if the assembly is equipped with the
appropriate taps (supplied on demand) placed on the hot water outlet and inlet.
To carry out the purge it is necessary to:
• close the cold water inlet
• drain the DHW system from the water contained therein by means of a hot water tap
• close the DHW outlet
• unscrew the two stop cocks caps
• remove the filters.
In case the appropriate tap is not supplied it is necessary to disassemble the DHW heat exchanger, as described in the fol-
lowing section, and do the purge aside. We recommend you also purge from limestone deposits the DHW heat exchanger
seat and the NTC sensor fitted on the DHW system.
To purge the exchanger and/or the DHW system we suggest the use of Cillit FFW-AL or Beckinser HF-AL.

16. how to disassemble the dhw heat exchanger

(not fitted on 1.310 Fi model)
The stainless steel plate-type DHW heat exchanger is easily disassembled with a screwdriver by operating as described
below:
• drain, if possible, only the boiler system, through the drain tap;
• drain the DHW system from water;
• remove the two screws (right in front of you) securing the DHW heat exchanger and pull it off its seat (figure 34).

17. cleaning the cold water filter

(not fitted on 1.310 Fi model)
The boiler is equipped with a cold water filter placed on the hydraulic assembly. To clean it do the following:
• drain the DHW system from water;
• unscrew the nut on the flow sensing assembly (Figure 34);
• pull out the flow sensing device and its filter;
• remove the impurities.
Important: in the event of replacements and/or cleaning of the O-rings on the hydraulic unit, do not use oil or grease as
lubricant but exclusively Molykote 111.
flow sensing securing nut
Figure 34
DHW heat exchanger securing screws
InstructIons pertaInInG to tHe Installer 95.188.3 - GB
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