Draining The Boiler; Hydraulic Unit ( Dhw); Cleaning The Cold Water Filter; Final Com M Issioning - UTICA BOILERS MAHF-75 Installation, Operation And Maintenance Manual

1 1 .6 H ydra ulic Unit ( DH W )
For special areas, where wat er is harder t han 200 ppm
or 12 grains/ gallon, inst all polyphosphat e dispenser or
equivalent t reat m ent syst em , com pliant wit h current
regulat ions.
1 1 .7 Clea ning The Cold W a t er Filt er
Boiler is fitted with cold water strainer located on DHW
hydraulic assem bly ( B) . To clean:
• Drain dom est ic hot wat er syst em . ( C - 115 & 150)
• 165 Drain is field supplied/installed.
• Rem ove nut on DHW priorit y sensor unit using 18
m m wrench. ( B)
• Pull out flow sensor and its filter.
• Soak in whit e vinegar or replace as necessary.
NOTICE
When replacing and/ or cleaning " O- rings" on
hydraulic assem bly ( DHW) , use only Molykot e
111 as a lubricant , not oil or grease.
1 1 .8 Fina l Com m issioning
• Allow heat ing syst em t o heat . Balance t he syst em
to achieve temperature difference across heating
supply and ret urn pipes at t he boiler.
• Check syst em for proper volum e and pressure. See
page 4 for accept able volum e and pressure.
• Turn off boiler.
• Thoroughly flush water pipe work. Clean filters in
heat ing ret urn and supply wat er isolat ing valves.
• Repressurize t he syst em .
1 1 .9 Fina l Assem bly
• Place front j acket in posit ion over boiler. Secure in
posit ion using screws previously rem oved.
• I f boiler is t o be left in service, set cont rols and
room t herm ost at .
• I f boiler is not t o be handed over im m ediat ely,
close boiler gas service valve and turn off electrical
supply.
• I f t here is possibilit y of boiler being left during frost
condit ions drain boiler and syst em . See sect ion
11.4 Draining t he boiler.Manufact urer recom m ends
at t aching a label t o t he boiler drawing at t ent ion t o
t he fact t hat t he syst em has been drained.
1 1 - GEN ERAL M AI N TEN AN CE AN D CLEAN I N G
M ode l M ACF- 1 5 0 Sh ow n
Hydraulic Assem bly ( Com bi- 150)
M ode l M ACF- 2 0 5
F E
Hydraulic Assem bly ( B)
A DHW Exchanger Fixing Screw
B DHW Priorit y Sensor Wit h Filt er
Boiler/ Syst em Drain Tap ( 150 Unit Only)
( C-1 & C-2: Access To Tap C - Bot t om Of
C
Boiler)
D Boiler / Syst em Filling Tap ( 150 Unit Only)
E DHW Tem perat ure NTC Probe
F Low Water Cutoff
6 3
A
B
LEGEN D
240013503 REV A, [ 03/ 15/ 2022]