31
Maintenance instructions
ENGLISH
Inspections and maintenance performed
professionally and according to a regular
schedule, as well as the use of original
spare parts, are of the utmost importance
for fault-free operation of the boiler and
to guarantee its long life.
Yearly maintenance of the appliance is
mandatory in compliance with Laws in
force.
4
INSPECTIONS AND MAINTENANCE
TABLE OF RESISTANCE VALUES, ACCORDING TO THE TEMPERATURE, TO THE HEATING PROBE 11 (SR)
AND TO THE DOMESTIC HOT wATER PROBE 1 (SS) AND ANY HEATING RETURN PROBE 22 (SRR) see par. 4.5.
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
Relation between the temperature (°C) and the nom. resistance (Ohm) of the heating probe SR and of the domestic hot
water probe SS
Example: At 25°C, the nominal resistance is 10067 Ohm At 90°C,the nominal resistance is 920 Ohm
4.1 - INSPECTION AND
MAINTENANCE INSTRUCTIONS
To assure long-term functioning of your appliance
and to avoid altering its approved status, only original
Unical AG S.p.A. spare parts must be used.
If a component needs to be replaced:
• Disconnect the appliance from the electrical mains
and make sure that it cannot be reconnected
accidentally.
• Close the gas shut-off valve upstream the boiler.
• If needed, and depending on the intervention to
be carried out, close any shut-off valves on the
flow and return line of the heating system, as well
as the cold water inlet valve.
• Remove the front casing from the appliance.
Once all maintenance operations are complete
resume boiler operation
• Open the heating flow and return pipes, as well
as the cold water inlet valve (if closed previously).
• Vent and, if necessary, restore the heating pres
-
sure until reaching a pressure of 0.8/1.0 bar.
• Open the gas shut-off valve.
• Switch the boiler back on.
• Make sure the appliance is gas tight and water
-
tight.
• Remount the front casing of the appliance.
Failure to perform Inspections and Main-
tenance can entail material and personal
damage.