Unical MODULEX EXT 150, Installation And Servicing Instructions

Page: 50 / 56

50
Servicing schedule
To ensure the continued safe and efficient
operation of the boiler it is highly recom-
mended that it is checked at regular intervals
and serviced when necessary, and that only
original spare parts are used.
The law in force states that the boiler must
be serviced annually.
If the boiler is not checked and serviced
when necessary it could cause material and
personal damages.
For this reason UNICAL recommends that a
servicing contract should be made with a heating installer.
The regular inspection is useful to determine the actual state of
an appliance and to compare it with an optimum state. This is
achieved through measurement, control and observation.
The service is necessary to eliminate eventual deviations of
the actual state from the optimum state. This is normally done
through the cleaning, the parameters setting and the eventual
replacement of single components subject to mechanical wear.
The frequency of servicing will be determined by the service
engineer and will depend on appliance’s state of condition.
4
INSTRUCTIONS FOR SERVICING
To ensure a long life to all your boiler compo-
nents and in order not to alter the conditions
of the approved product only original UNICAL
spare parts must be used.
After having carried out all the necessary maintenance, always
follow these steps:
• Switch OFF the main switch
• Isolate the boiler from mains via a device having, at least,
a 3 mm in the switch contacts (e.g.: safety devices or power
switches) and make sure it cannot be switched ON acciden-
tally.
• Switch off the gas gate valve upstream the boiler.
- If necessary, and in function of the type of work to be
carried out, close any on-off valves fitted on the CH flow
and return pipes, as well as the cold inlet valve.
- Remove the appliance’s front panel.
After maintenance works have been finished, follow the next
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
heating system’s pressure until a pressure of 0,8/1 bar
is reached.
- Open the on-off gas valve.
- 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.
SERVICING
SCHEDULE
Relation between the temperature (°C) and the nom. resistance
(Ohm) of the heating sensor SR and the return heating sensor
SRR.
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 THE RESISTANCE VALUES IN FUNCTION OF THE HEATING SENSOR (SR) AND RETURN HEATING SENSOR
TEMPERATURE (SRR)
Example: At 25°C, the nominal resistance is 10067 Ohm
At 90°C, the nominal resistance is 920 Ohm