INSTALLATION INSTRUCTIONS
26
4.4 Frost Protection
The boiler is protected from freezing by electronic board settings and special functions that provide the starting of
the burner to heat all the interested parts, when their temperature drops below the minimum preset values,
protecting the boiler up to an external temperature of -10°C.
The device operates as follows:
•
The heating circuit water temperature drops below 5 °C, the burner is automatically switched ON until the water
reaches a temperature of 30°C.
•
The domestic hot water temperature drops below 4°, the burner is automatically switched ON until the water
reaches a temperature of 8°C.
The system operates even if the boiler is in OFF mode, as long as it is electrically powered (230 V)
and the gas supply is open.
In case of long periods of inactivity, it is recommended to empty the boiler and the hydraulic
system.
Warning for the service technician
In case of a boiler locked out because of freezing, before putting it into operation, make sure that any part is
blocked by ice (heat exchanger, pump, etc.).
Warning for the installer
In case of an outdoor boiler installation, where temperatures can drop below -10°C, it is recommended to fill the
hydraulic system with an antifreeze inhibitor (see below Table for the dilution percentage) and to install a Heating
elements kit (code 82259LP).
Table
Antifreeze
Temperature
Ethylene glycol
(%) volume
freezing point
(°C)
boiling point
(°C)
10
- 4
101
20
- 10
102
30
- 17
104
40
- 27
106
50
- 40
109
60
- 47
114
Recommended Glycol 20% percentage for temperatures up to -10°C.
Summary of Contents for RK 25 /B
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