SCHUSTER SWG A 23 - Page 29

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ENGLISH
MAINTENANCE INSTRUCTION
ROUTINE YEARLY VERIFICATION OPERATIONS
COMPONENT: VERIFY: CONTROL/INTERVENTION
METHOD:
FL
(domestic hot water
priority ow switch ( 2 )
Is the minimum domestic hot water
ow rate 3 l/min.?
The burner must ignite with an
intake above or equal to: 3 l/min.
VG
(Gas valve) ( 3 )
Does the valve modulate properly? Open a hot water tap at maximum
flow rate and then at minimum.
Make sure that the ame modu-
lates.
SR (heating sensor) ( 11 )
SS (domestic hot water sensor)
( 1 )
Do the sensors maintain the origi-
nal characteristics?
12571 ohm at 20° C / 1762 ohm
at 70° C.
Measurement to be taken with the
wires disconnected (see table Res/
Temp).
E ACC/RIV. (ignition/detection
electrode) ( 4 )
Does the discharge of sparks be-
fore
putting the boiler in safe conditions
last less than 10 sec.?
Detach the electrode ionisation
wire and check the securing time.
TL (anti-overheating
limit thermostat) ( 10 )
Does the TL put the boiler in safety
conditions when overheating?
Heat the TL until it intervenes at
95°C and check that it intervenes
at 95°.
DK (safety pressure switch
against water deciency) ( 13 )
Does the pressure switch block the
boiler if the water pressure is below
0.4 bar?
Without request: close the shut-off
valves of the heating circuit, open
the drain valve to make the water
pressure decrease. Before pres-
surising again, check the pressure
of the expansion vessel.
Expansion vessel ( 8 ) Does the vessel contain the right
amount of air?
Check the nitrogen pressure (1 bar
when the boiler is empty). Pres-
surise the boiler (open the pump
automatic vent valve). Open the
heating circuit closing valves.
Domestic hot water ow rate Filter in cold water inlet ( 2 ) Clean the lter with limescale re-
mover.
Heat exchanger body ( 9 ) Check that the space between the
rungs of the exchanger are not
clogged
Eliminate the deposits without
damaging the exchanger, using a
soft bristle brush and specic, non
ammable detergents.
Burner ( 5 ) Check the state of cleanliness of
the burner mesh
Remove deposits using a soft bris-
tle brush and blow on each single
ramp from the outside and from
the venturi.
( Num ) = see key Par. 2.2