Removing Scale; Specific Maintenance Operations - Baxi PRIME Series Installation Manual

Cleaning the filters
The DHW and CH filters are housed in special extractable cartridges. The CH cartridge is located on the CH return line (C) while
the DHW cartridge is on the cold water inlet (B). Clean the filters as follows:
• Disconnect the boiler from the mains power supply;
• Shut the DHW inlet tap;
• Close the inlet and outlet taps of the CH system (when applicable);
• Drain the water in the CH circuit by opening the tap (F);
• Remove the clips (1-B) and (1-C) as shown in the figure and remove the cartridges (2-B) and (2-C) containing the filters,
making sure not to exert excessive pressure;
• To extract the heating filter cartridge, it is advisable to first remove the 3-way valve motor (1-2-3-D);
• 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 fill the system with water, remove the knob (1-E) by hand, pulling it downwards (do not use tools) and turning it anticlockwise
(half a turn is sufficient) to set the required pressure. Close the valve returning the knob to its original position.
When replacing and/or cleaning the O-rings on the hydraulic assembly, only use Molykote 111 as a lubricant, not oil or
grease.

Removing scale

The DHW circuit can be cleaned by undoing the two front screws (G) on the water-water exchanger and removing this from its
seat. To clean, proceed as follows:
• Isolate the unit from the electrical mains (disconnect the boiler from the main elecrical supply).
• Cut off the gas supply to the boiler.
• Close the inlet and outlet taps of the CH system.
• Drain the water in the CH circuit by opening the tap (F);
• Turn off the DHW inlet tap.
• Drain the DHW system by opening a hot water tap.
• Remove the exchanger undoing the two Ø 6 mm Allen screws.
• Reassemble the burner following the above procedure in reverse order.
10.3.9 Distance of electrodes
8.0
±1
BO-7637873

10.4 Specific maintenance operations

10.4.1 Replacing the ignition/sensor electrode
Replace the ignition/flame-sensing electrode in the following cases:
• Ionisation current <3 μA.
• Worn electrode.
Open the cover on the top fan and remove the plug of the electrode and the earth wire. Undo the 2 screws on the ignition electrode
and remove this. Assemble the new electrode with the seal. Perform reassembly following this procedure in reverse order.
4.5
±0.5
43 7696306 (01-12/17)