Maintenance Instructions (For Authorised Personnel); Draining The Appliance; Replacing Parts (When Necessary); Routine Maintenance - Ariston NUOS Serie Manual De Instrucciones

8. MAINTENANCE INSTRUCTIONS (for authorised personnel)

WARNING! Follow the general warnings and the safety instructions listed in the previous
!
paragraphs and strictly adhere to the indications therein contained.
All maintenance operations and activities must be performed by qualified staff (i.e. possessing the necessary
skills as specified by the regulations in force).

8.1 Draining the appliance

The appliance must be drained if it is to be left unused in environments subject to frost.
When necessary, drain the appliance as follows:
- Disconnect the appliance from the mains supply.
- Close the shut-off valve D (Fig. 16), if installed, or the central tap of the domestic water supply network.
- Open the hot water tap (wash basin or bathtub).
- open tap B (Fig. 16).

8.2 Replacing parts (when necessary)

!
WARNING! Disconnect the appliance from the power supply before carrying out repairs or
maintenance work.
With reference to Fig. 17, when intervening on the NTC temperature sensor (K), disconnect the wire (F) from the PCB
and remove it from its housing while making sure not to bend it excessively.
To intervene on the display PCB (W), disconnect the wire (Y) and loosen the screws.
To intervene on the motherboard (Z), disconnect the wires (C,Y, F, P, Q, R, S, T) and loosen the screws.
When reassembling, make sure that all components are replaced in their original position.
Drain the appliance before intervening on the heating element and anode.
After loosening the 5 bolts (C, Fig. 18), remove the flange (F, Fig. 18) to which the heating element and anode are
attached.
When reassembling, make sure that the heating element and flange seal are replaced in their original position (Fig.
18). It is advisable to replace the flange after each removal of the flange.
Use original spare parts only

8.3 Routine maintenance

The following operations should be carried out to ensure the efficient operation of the appliance:
a) Heating element (R, Fig. 18):
descaling of the heating element every two years, making sure not to damage its casing; alternatively, use suitable
acidic substances.
TECHNICAL INFORMATION FOR INSTALLERS
page 61