Description of functioning
t e c h n i c a l
8
Drain valve:
This component allows the heating circuit to be drained.
Finger operated located to the right hand side of the
safety valve. (Part number MCB2180)
3 Way valve:
I
ntegrated within hydraulic unit, operates whenever a hot
tap is opened.
This action activates the micro switch and ports the primary
circuit away from the radiators to the plate heat exchanger
In order to produce hot water at the taps.
(Part number MCB219
1
Complete unit)
Micro switch
Located on the 3 way valve brass diaphragm housing. Activation
oc
c
urs when the white switch tip which sits on the diaphragm
push rod in CH mode is released as the diaphragm push rod
ports the 3 way valve to DHW.
This action places the PCB into DHW mode allowing the boiler
to commence the ignition sequence
(Part number MCB2320)
.
Flow restrictor
Located within the hydraulic unit between the brass inlet
union and the cold inlet port on the hydraulic unit.
This component restricts the flow of water into the boiler
to 10 litres per min
(Part number MCB2240)
NOTE
THIS RESTRICTOR IS NOT SUPPLIED WITH NEW
HYDRAULIC UNITS. ALWAYS ENSURE THAT THIS ITEM
IS REPLACED INTO THE HYDRAULIC UNIT IF ANY WORK IS
CARRIED OUT ON THE HYDRAULIC UNIT
MCB2240
MCB2320
MCB2180
7