Wolf CGU-2-18 Installation And Maintenance Instructions Manual page 55

Cleaning the DHW heat exchanger
Subject to the water quality it may be advisable to
regularly descale the DHW heat exchanger on the
DHW side.
For this the disassembly of the hydraulic group is
required.
Take the hydraulic assembly apart as follows:
Hydraulically depressurise the system, collecting
-
water in a suitable container.
Switch OFF the mains electrical isolator.
Close the gas valve, paying attention to safety
instructions.
- Pull out all 4 interlocking brackets (2) approx. 2 cm
(see arrows - do not dismantle)
- Unlock both safety catches (3) by turning the
screws to the left (see both views - SW 6)
- Pull out brackets (4) for sensors and
thermomanometer to the right and remove them
- Open expansion vessel screw connection (5)
and pull forward (SW 24)
- Open gas screw connection (6)
and turn to the side (SW 24)
- Open piping safety valve (on-site)
Remove alternative valve (7) by undoing the
brackets
- Interlocking of flow and return (8) open by turning
90° to left, then press pipes to the side
(pay attention to O-rings)
- Disconnect electric connector cables (9) from
diverter valve, water sensor, pump, etc.
(Plugs are encoded to prevent confusion)
- Now pull complete hydraulic group upwards
by shaking it lightly, then remove forwards
- Release the two fixing screws (10) on the
disassembled hydraulic group with a 4 mm Imbus
Allen key
3062347_0309
Maintenance
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55