Hydraulic Unit (Dhw); Cleaning The Cold Water Filter; Final Commissioning; Final Assembly - UTICA BOILERS MAHF-165 Installation, Operation And Maintenance Manual

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.

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. (C - 150 only)
• Remove the flow sensor on top of assembly.
• Remove nut on DHW priority sensor unit using 18 mm
wrench. (B)
• Pull out flow sensor and its filter.
• Soak in white vinegar and water mixture for 20 minutes.
NOTICE
When replacing and/or cleaning "O-rings" on hydraulic
assembly (DHW), use only Molykote 111 as a lubricant,
not oil or grease.

11.8 Final Commissioning

• Perform Automatic Calibration function as detailed in
section 9.8.
• 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.
• 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.
11 - GENERAL MAINTENANCE AND CLEANING
Model MACF-150
H H F F E E
Hydraulic Assembly (Combi-150)
A DHW Exchanger Screw
B DHW Priority Sensor
C
Boiler/System Drain Tap
D Controlled Fast Fill
E DHW Temperature NTC Probe
F Low Water Pressure Cutoff
G
DHW Cold Inlet
H DHW Outlet
Model MACF-205
F
E
Hydraulic Assembly (B)
A DHW Exchanger Fixing Screw
B DHW Priority Sensor With Filter
Boiler/System Drain Tap (150 Unit Only)
C
(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
52
A A
B B
D D C C
LEGEND
A
B
LEGEND
240012874 REV A, [01/31/2020]
G G