281
cod. 3540000251 - Rev. 00 - 03/2024
EN
ALHENA C
Periodic inspection
To ensure proper operation of the unit over time, have qualified personnel carry out a yearly ins-
pection, providing for the following checks:
• The control and safety devices (gas valve, flow meter, thermostats, etc.) must function cor-
rectly.
• The fume exhaust circuit must be perfectly efficient.
• The sealed chamber must be tight.
• The air-fume end piece and ducts must be free of obstructions and leaks
• The burner and exchanger must be clean and free of deposits. Use suitable brushes for clea-
ning. Never use chemical products.
• The electrode must be properly positioned and free of any deposits.
The electrode can be cleaned of incrustations only with a non-metallic brush, and must NOT
be sanded.
• The gas and water systems must be tight.
• The water pressure in the system when cold must be approx. 1 bar; otherwise bring it to that
value.
• The circulating pump must not be blocked.
• The expansion vessel must be filled.
• The gas flow and pressure must match that given in the respective tables.
• The condensate evacuation system must be efficient with no leaks or obstructions.
• The trap must be full of water.
• Check the quality of the water in the system.
• Check the condition of the exchanger insulation.
• Check the gas connection between the valve and Venturi.
• Replace the burner gasket if damaged.
• After checking, always control the combustion parameters (see "checking the combustion va-
lues").
3.4 Troubleshooting
Diagnostics
LCD Off
Make sure the card is powered: using a digital multimeter, check for the presence of supply volta-
ge.
In case of no voltage, check the wiring.
If the voltage is sufficient ( Range 195 – 253 Vac), check the fuse
(3.15AL@230VAC)
. The fuse
is on the card. To access it, see fig. 20.
LCD display On
In case of operation problems or faults, the display flashes and the fault identification code appe-
ars
There are faults that cause permanent shutdown (indicated with the letter “
A
”): to restore opera-
tion just press the
reset
button (detail 6 - fig. 1) for 1 second or use the RESET on the remote
timer control (optional) if installed; if the boiler does not restart, it is necessary to eliminate the fault
first.
Other faults cause temporary shutdowns (marked with the letter “
F
”) which are automatically reset
as soon as the value returns within the boiler's normal working range.
