DORA TECH
90 LT - 120 LT
cod. 3540000800 - Rev. 02 - 09/2023
104
EN
ATTENTION
Carrying out repair work on
parts with safety function
compromises safe operation
of the equipment. Only replace
defective parts with original
spare parts.
7.1
POWER BOARD FUSE REPLACEMENT
Proceed as indicated below (reserved for qualified technical
personnel only):
• Disconnect the power to the device.
• Remove the bottom cover.
• Remove the fuse cap, then the fuse, using a suitable screw-
driver.
• Install a new IEC 60127-2/II
(T5AL250V)
certified time-de-
lay
5 A 250V
fuse, then refit the protective cap.
• Reassemble all the plastics and make sure the equipment is
correctly installed before powering it.
fig. 64
7.2 REPLACEMENT OF ELECTRIC Heater SAFE-
TY THERMOSTAT
This equipment has a manual-reset safety thermostat connect-
ed in series with the heating element immersed in water, which
interrupts the power supply in case of overtemperature inside
the tank.
If necessary, proceed as follows to reset the thermostat (re-
served for qualified technical personnel):
• Unplug the product.
• Remove the bottom cover by first undoing the locking
• Manually reset the tripped safety thermostat (fig. 65). In
case of tripping, the central pin of the thermostat comes out
by about 2 mm.
• Refit the previously removed bottom cover.
fig. 65- Safety thermostat reset
ATTENTION
The intervention of the safety
thermostat may occur due to a
fault in the control board or the
absence of water in the boiler
tank.
NB!: The intervention of the thermostat ex-
cludes the operation of the electrical heater
but not the heat pump system within the al-
lowed operating limits.
ATTENTION
If the operator is unable to elim-
inate the fault, switch off the
equipment and contact the Tech-
nical Assistance Service, com-
municating the model of the
product purchased.
7.3 CHECK/REPLACEMENT OF THE
SACRIFICIAL ANODE
The integrity of the Mg anodes must be checked at least
once every two years (once a year is recommended). The
check should be carried out by a qualified technician.
The magnesium anode (Mg), also known as an “sacrificial” an-
ode, prevents any eddy currents generated inside the boiler
from triggering surface corrosion.
Magnesium is, in fact, a less noble metal than the material lin-
ing the inside of the boiler, therefore, it attracts the negative
charges first that are formed by heating the water, and is con-
sumed. The anode, therefore, “sacrifices” itself and corrodes
instead of the boiler tank. The integrity of the Mg anode must
be checked at least every two years (preferably once a year).
The operation must be performed by qualified personnel.
