Immergas 3.025499, Instruction And Recomendation Booklet

Page: 40 / 68

40
+
+
3
12
2
1
P1
P3
+
+
3
12
1
P1
2
P3
3-4
INS
TALLER
US
ER
MAINTEN
AN
CE TECHNI
CI
AN
3.4 TROUBLESHOOTING.
N.B.: maintenance operations must be carried
out by an authorised company (e.g. Authorised
After-Sales Technical Assistance Service).
- Smell of gas. Caused by leakage from gas circuit
pipelines. Check sealing efficiency of gas intake
circuit.
- Repeated ignition blocks. No gas, check the
presence of pressure in the network and that
the gas adduction cock is open. Incorrect
adjustment of the gas cock, check the correct
calibration of the gas valve.
- Irregular combustion or noisiness. It may be
caused by: a dirty burner, incorrect combustion
parameters, intake-exhaust terminal not cor-
rectly installed. Clean the above components
and ensure correct installation of the terminal,
check correct setting of the gas valve (Off-Set
setting) and correct percentage of CO
2
in flue
gas.
- Frequent interventions of the overheating
safety thermostat. It can depend on the lack
of water in the boiler, little water circulation
in the system or blocked pump. Check on the
manometer that the system pressure is within
established limits. Check that the radiator
valves are not closed and also the functionality
of the pump.
- Drain trap clogged. This may be caused by
dirt or combustion products deposited inside.
Check, by means of the condensate drain cap,
that there are no residues of material blocking
the flow of condensate.
- Heat exchanger clogged. This may be caused
by the drain trap being blocked. Check, by
means of the condensate drain cap, that there
are no residues of material blocking the flow of
condensate.
- Noise due to air in the system. Check opening
of the special air vent valve cap (Part. 37 Fig.
1-30). Make sure the system pressure and ex-
pansion vessel pre-charge values are within the
set limits; The factory-set pressure values of the
expansion vessel must be 1.0 bar, the value of
system pressure must be between 1 and 1.2 bar.
Check that system filling and air bleeding has
been performed according to the requirements.
- Noise due to air inside the condensation
module. Use the manual air vent valve (Part.
12 Fig. 1-30) to eliminate any air present in the
condensation module. When the operation has
been performed, close the manual vent valve.
- Domestic hot water probe faulty. In order to
replace the DHW probe, the storage tank does
not have to be emptied as the probe is not in
direct contact with the DHW inside the storage
tank.
3.5 CONVERTING THE BOILER
TO OTHER TYPES OF GAS.
If the boiler has to be converted to a different gas
type to that specified on the data plate, request
the relative conversion kit for quick and easy
conversion.
The gas conversion operation must be carried
out by an authorised company (e.g. Authorised
After-Sales Technical Assistance Service).
To convert to another type of gas the following
operations are required:
- disconnect the appliance;
- replace the nozzle located between the gas pipe
and gas/air mixing sleeve (Part. 16 Fig. 1-30),
taking care to disconnect the appliance during
this operation;
- re-power the appliance;
- calibrate the number of fan revolutions (parag.
3.6):
- adjust the correct air/gas ratio (parag. 3.7);
- seal the gas flow rate regulation devices (if set-
tings are modified);
- after completing the conversion, apply the
sticker, contained in the conversion kit, near
the data nameplate. Using an indelible marker
pen, delete the data relative to the old type of
gas.
These adjustments must be made with reference
to the type of gas used, following that given in
the table (Par. 3.21).
3.6 CALIBRATION OF NUMBER OF FAN
REVS.
Attention: Verification and calibration is neces-
sary, in the case of transformation to other types
of gas, in the extraordinary maintenance phase
with replacement of the PCB air/gas circuit com-
ponents or in the case of installations with fume
extraction systems, with horizontal concentric
pipe measuring more than 1 metre.
The boiler heat output is correlated to the length
of the air intake and flue exhaust pipes. This
decreases with the increase of pipe length. The
boiler leaves the factory adjusted for minimum
pipe length (1m). It is therefore necessary, espe-
cially in the case of maximum pipe extension, to
check the ∆p gas values after at least 5 minutes
of the burner operating at nominal heat output,
when the temperatures of the intake air and ex-
haust flue gas have stabilised. Adjust the nominal
and minimum heat output in the domestic hot
water and central heating modes according to
the values in the table (Par. 3.21) using the dif-
ferential manometers connected to the ∆p gas
pressure points (34 and 35 Fig. 1-30).
Access the configurations menu under the “SER-
VICE" item and adjust the following parameters
(Par. 3.21):
- boiler maximum heat output “P62”;
- boiler minimum heat output “P63”;
- maximum central heating output “P64”;
- minimum central heating output “P65”;
Below find the default settings present on the
boiler:
P62
G20:
5500 (rpm)
LPG:
5000 (rpm)
P63
G20:
1000 (rpm)
LPG:
1000 (rpm)
P64
G20:
5000 (rpm)
LPG:
4500 (rpm)
P65
G20:
1000 (rpm)
LPG:
1000 (rpm)
3.7 ADJUSTMENT OF THE AIR-GAS
RATIO.
Calibration of the minimum CO
2
(minimum
heating power).
Enter the chimney sweep stage without with-
drawing domestic hot water and take the heat-
ing selector switch to minimum (turn them in
anticlockwise until "0" appears on the display).
To have an exact value of CO
2
in the flue gases the
technician must insert the sampling probe to the
bottom of the sample point, then check that the
CO
2
value is that specified in the table, otherwise
adjust the screw (3 Fig. 3-4) (Off-Set adjuster).
To increase the CO
2
value, turn the adjustment
screw (3) in a clockwise direction and vice versa
to decrease it.
Key:
1 - Gas valve inlet pressure
point
2 - Gas valve outlet pressure
point
3 - Off/Set adjustment screw
12 - Outlet gas flow rate regu-
lator
HONEYWELL VK8205 Gas Valve SIT 848 Gas Valve