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240012994 Rev. B [08/31/2020]
11 - GENERAL MAINTENANCE AND CLEANING
11.6 Hydraulic Unit (DHW)
For special areas, where water is harder than 200 ppm or 12
grains/ gallon, install polyphosphate dispenser or equivalent
treatment system, compliant with current regulations.
LEGEND
A
DHW exchanger fixing screw
B
DHW priority sensor with filter
C Boiler/system drain tap (150 unit only)
(C-1 & C-2: access to tap C - bottom of boiler)
D
Boiler / system filling tap (150 unit only)
E DHW temperature NTC probe
F
Low water cutoff
11.7 Cleaning The Cold Water Filter
Boiler is fitted with cold water filter located on DHW hydraulic
assembly (B). To clean:
• Drain domestic hot water system.
•
Remove nut on DHW priority sensor unit using 18 mm
wrench. (B)
•
Pull out flow sensor and its filter.
• Remove any impurities.
•
Soak in white vinegar or replace as necessary.
11.8 Final Commissioning
•
Allow heating system to heat. Balance the system to
achieve temperature difference across heating supply and
return pipes at the boiler.
•
Check system for proper volume and pressure. See page 4
for acceptable volume and pressure.
•
Turn off boiler.
•
Thoroughly flush water pipe work. Clean filters in heating
return and supply water isolating valves.
• Repressurize the system.
11.9 Final Assembly
•
Place front jacket in position over boiler. Secure in
position at top using screws previously removed.
• If boiler is to be left in service with the User, set controls
and room thermostat.
• If boiler is not to be handed over immediately, close boiler
gas service valve and turn off electrical supply.
•
If there is possibility of boiler being left during frost
conditions drain boiler and system. See section
11: Component Replacement Or Periodic Cleaning.
Manufacturer recommends attaching a label to the boiler
drawing attention to the fact that the system has been
drained.
Model 150 Shown
Model 205 Shown
B
A
Hydraulic Assembly (B)
F
E
NOTICE
When replacing and/or cleaning “O-rings” on hydraulic
assembly (DHW), use only Molykote 111 as a lubricant,
not oil or grease.