38
Inspections and servicing schedule
Relationship between the temperature (°C) and the nominal
resistance (Ohm) of the CH sensor and the DHW sensors.
T°C
0
1
2
3
4
5
6
7
8
9
0
32755
31137
29607
28161
26795
25502
24278
23121
22025
20987
10
20003
19072
18189
17351
16557
15803
15088
14410
13765
13153
20
12571
12019
11493
10994
10519
10067
9636
9227
8837
8466
30
8112
7775
7454
7147
6855
6577
6311
6057
5815
5584
40
5363
5152
4951
4758
4574
4398
4230
4069
3915
3768
50
3627
3491
3362
3238
3119
3006
2897
2792
2692
2596
60
2504
2415
2330
2249
2171
2096
2023
1954
1888
1824
70
1762
1703
1646
1592
1539
1488
1440
1393
1348
1304
80
1263
1222
1183
1146
1110
1075
1042
1010
979
949
90
920
892
865
839
814
790
766
744
722
701
TABLE OF RESISTANCE VALUES AS A FUNCTION OF THE HEATING SENSOR (SR) AND DHW (SS) TEMPERATURE
SENSORS
Example: At 25°C, the nominal resistance is 10067 Ohm
At 90°C, the nominal resistance is 920 Ohm
To ensure the continued safe and efficient
operation of the boiler it is highly
recommended that it is checked at regular
intervals and serviced when necessary, and
that only original spare parts are used.
Regular attention will prolong the life of the
boiler.
If the boiler is not checked and serviced
regularly it could cause material and
personal damages.
For this reason UNICAL recommends that a servicing contract
should be made with our authorized After Sales Service
Assistance Centre.
The boiler must have regular maintenance and cleaning in order
to ensure reliable and efficient operation. Regular attention
will prolong the life of the boiler.
The frequency of servicing will be determined by the service
engineer and will depend on the appliance’s state of condition.
4
INSPECTION AND SERVICING SCHEDULE
INSTRUCTIONS FOR INSPECTION AND
SERVICING
To ensure a long life to all your boiler
components and in order not to alter the
conditions of the approved product, only
original UNICAL spare parts must be used.
Before servicing always carry out the following steps:
-
Disconnect the mains electricity supply.
-
Separate the appliance from the electrical supply by me-
ans of a separating device with an opening contact of at
least 3 mm (for example safety devices or power switches)
and ensure yourself that it cannot be accidentally reinser-
ted.
-
Close the on-off valve fitted upstream of the boiler.
-
If necessary, and in function of the type of work to be car-
ried out, close any on-off valves fitted on the CH flow and
return pipes, as well as the cold water inlet valve.
-
Remove the appliance’s front panel.
After having carried out all the necessary maintenance work
always follow these steps:
-
Open the CH flow and return valves as well as the cold inlet
valve (if previously closed),
-
Purge and, if necessary, proceed with restoring the hea-
ting system’s pressure until a pressure of 0,8/1 bar is rea-
ched.
-
Open the on-off gas cock.
-
Reconnect the appliance to the electrical supply and switch
on the mains electrical supply.
-
Test for gas soundness, on the gas side and on the water
side.
-
Replace the appliance’s front panel.