6.4 Heat exchanger
See the procedure in paragraph 6.1
6.5 Flue gas temperature sensor
The fl ue gas temperature sensor is located in the fl ue and does not require periodical maintenance.
If the sensor needs to be replaced due to a fault, proceed as follows:
• stop the humidifi er by moving the rocker switch on the control panel to 0 and then checking that the
display is off;
• open the electrical compartment to access to the panel;
• loosen terminals 10T and 11T (or 10Z and 11Z) (see the wiring diagram) on the terminal block in
the bottom of the electrical panel and the probe holder nut on the adapter joint (see the spare parts
manual, code +030220532) and then remove the probe and the electrical cable.
Then replace the sensor by following the same procedure in reverse.
6.6 Water temperature sensor
This does not require periodical maintenance.
To replace the sensor, proceed as follows:
• stop the humidifi er by moving the rocker switch on the control panel to 0 and then checking that the
display is off;
• open the panels to access the water circuit (Fig. 6.a);
• using the Velcro strip on the insulation (left wall of the cylinder), open enough insulation to allow good
visibility of the sensor (see the spare parts manual, code +030220532);
• use a special tool to remove the probe-holder split pin, and then remove the sensor from its housing;
• loosen terminals 12T and 13T (see the wiring diagram) on the terminal block in the bottom and
remove the probe.
Then replace the sensor by following the same procedure in reverse.
6.7 Fuses
IFuses 1, 2, 3 measure 10.3x38 mm and are contained inside the fuse carrier; while fuse 4 measures
6.3x20 mm; to check the fuses, test continuity using a tester.
Use fuses with the ratings indicated in Table 7.a.
model
UG045
fuses 1 and 2
Slow-blow, 3 A
fuse 3
Fast-blow, 1A
fuse 4
Slow-blow, 3.15A
6.8 Cooling fan
The cooling fan starts when the unit is switched on, and is used to keep the operating temperature of the
electrical panel and the electronics within the designed limits.
If the fan is faulty:
• disconnect the electrical connections;
• replace the fan after having unscrewed the fastening screws;
N.B: being thermally protected, the fan may switch off temporarily if it overheats, and then will start
again after having cooled down.
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gaSteam HARDWARE +030220538 - rel. 1.4 - 22.01.2008
Table 7.a