Checking And Cleaning; Dismantling The Flame Sensor - Riello DB 3 SE FGR Installation, Use And Maintenance Instructions

6.2.4

Checking and cleaning

The operator must use the required equipment
during maintenance.
Combustion
The optimum calibration of the burner requires an analysis of the
flue gases.
Significant differences with respect to the previous measure-
ments indicate the points where most care should be exercised
during maintenance.
Combustion head
Open the burner and make sure that all components of the
combustion head are in good condition, not deformed by the
high temperatures, free of impurities from the surroundings
and correctly positioned.
Burner
Clean the outside of the burner.
Fan
Check to make sure that no dust has accumulated inside the fan
or on its blades, as this condition will cause: a reduction in the air
flow rate and provoke polluting combustion.
Boiler
Clean the boiler as indicated in its accompanying instructions, es-
pecially in order to maintain all the original combustion character-
istics intact.
Flame sensor
Minimum current for correct working is 70 µA.
If the value is lower, it could be due to:
– Exhausted sensor;
– Low voltage (lower than 187 V);
– Bad regulation of the burner.
In order to measure the current, use a microammeter of 100 µA d.c.,
connected in series to the sensor, as in the layout, with a capacitor
of 100 µF - 1V d.c. at the same level of the instrument (Fig. 28).
D1143
Maintenance
Gas leaks
Make sure that there are no gas leaks on the pipe between the
gas meter and the burner.
Gas filter
Change the gas filter when it is dirty.
Combustion
In case the combustion values found at the beginning of the inter-
vention do not respect the standards in force or, in any case, do
not correspond to a proper combustion, contact the Technical As-
sistance Service in order to carry out the necessary adjustments.
EN 676
Theoretical max
CO
GAS
0 % O
G 20 11.7
G 25 11.5
G 30 14.0
G 31 13.7
6.2.5

Dismantling the flame sensor

To dismantle the sensor 1)(Fig. 29) after disconnecting it electri-
cally, loosen the screws 2) and turn everything to remove it from
its support.
Fig. 28
26 GB
Air excess
Max. output. Max. output.
 1.2
CO % Calibration
2
2
 = 1.2
2
9.7
9.5
11.6
11.4
20111854
1
CO
 1.3
mg/kWh
 = 1.3
 1000
9
 1000
8.8
 1000
10.7
 1000
10.5
Tab. L
2
Fig. 29
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