Unical ALKON 28 R HE, Installation And Servicing Manual

Page: 38 / 44

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.
These adjustments can be performed only by Service Centres
authorized by UNICAL.
UNICAL is not responsible for any damages caused to
persons, animals and goods deriving from this infringement.
For a better operation of your appliance follow the suggested
servicing as shown on page 39
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.