Radiant RKR 25, User Manual

USER INSTRUCTIONS

3

Starting - up the boiler 



  Open the gas Isolation valve located under 

the boiler. 



  Switch on the boiler by placing the ON/OFF 

switch (

1

)

in the 

ON

 position (see “Control 

panel”). 



  The boiler will light automatically (with the 

WINTER mode selected and room thermostat 
connected). 



  Check that there are no flashing numbers on 

the display 

8

 (see error codes). If code 

H2O

appears on the display 

8

 this denotes that 

there is no water in the boiler. Consequently, 
fill the system as described in section “Filling 
the system”. 

■

“SUMMER” mode  

To switch boiler operation to “SUMMER” mode, press button 

6

 (see fig. 1). The boiler will only work for the D.H.W 

system. The “SUMMER” mode setting of the boiler is signalled by the symbol

lit continuously on the control 

panel.  

The automatic ignition system will light the burner every time there is a demand for domestic hot water. In this 

case, the symbol

on the control panel will flash.  

■

“WINTER” mode 

To switch boiler operation to “WINTER” mode, press button 

6

 (see fig. 1). The boiler will only work for the central 

heating system. The “WINTER” mode setting of the boiler is signalled by the symbol

lit continuously on the 

control panel. 

The automatic ignition system will light the burner every time there is a demand for room heating. In this case, the 

symbol

on the control panel will flash. 

■

“SUMMER-WINTER” mode  

To switch boiler operation to “SUMMER/WINTER” mode, press button 

6

 (see fig. 1). The boiler will work for both 

central heating/D.H.W systems. The “SUMMER/WINTER” mode setting of the boiler is signalled by the symbols 

lit continuously on the control panel. 

The automatic ignition system will light the burner every time there is a demand for room heating or domestic hot 

water, the functioning is signalled by the symbols 

flashing continuously on the control panel. 

■

Regulating the heating temperature 

The heating temperature is regulated by knob 

2 

(see fig.1). 



  Rotating the knob anticlockwise reduces the temperature. 



  Rotating the knob clockwise increases the temperature. 



  The range of temperature settings for the central heating runs from a minimum of 30°C to a maximum of 80°C, 

or, in the case of low temperature operation, from a minimum of 25°C to a maximum of 59°C. 

6

7

5

4

3

2

1

8

Fig. 1