Description of functioning
t e c h n i c a l
50
3.3- Assembly and disassembly instructions
PLEASE NOTE THAT THE HYDRAULIC UNIT CONTAINS A FLOW RESTRICTOR.
THIS IS LOCATED IN THE COLD WATER INLET PORT WITHIN THE UNIT.
FAILURE TO REFIT THIS PART WILL ALLOW AN EXCESSIVE FLOW FROM THE
BOILER. THIS WILL RESULT IN TEPID OR LUKE WARM WATER AT TAPS UNLESS
THE FLOW IS RESTRICTED AT TAP.
.
Changing the entire hydraulic unit:
- Drain the heating circuit and the DHW
circuit.
- Unplug the boiler from the mains.
- Disconnect the electrical connections,
i.e. the 3-way valve micro switch and
thermistor connections.
- Remove the heating return pipe (1)
and the heating outlet pipe (2) from the
hydraulic unit.
- Remove the pressure sensor from the heating return pipe for ease of handling.
- Remove the heating outlet pipe (3) from the main heat
exchanger, for ease of handling.
- Remove the screws holding the hydraulic unit to the
boiler base (they are on the underside).
- Release the hydraulic unit from the lower connectors
(DHW inlet and outlet and heating inlet and outlet).
The water intake connectors do not need to be remo-
ved.
Changing the plate heat exchanger and the 3-way valve diaphragm:
To change these elements, part of the hydraulic unit must fi rst be disassembled. The
whole unit is divided into two parts: unit 1 and unit 2 (see photograph 25).
Disassembling unit 1: (see photographs 23 and 24)
- Drain the heating circuit and the DHW circuit.
- Unplug the boiler from the mains.
- Disconnect the electrical connec-
1
2
r
Group 1
Group 2
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