Unit installation
User, Installation and Service Manual for F1 Gas Unit Heaters  5
Ed. 05/2009 
SAFETY AND CONTROL DEVICES 
-  High temperature limit switch: 100°C with manual reset (prevents the overheating of the heat 
exchangers) 
-  Pressure differential switch: for the control of the correct flue fan operation; when fan not 
operates correctly or the flue/air inlet ducts are obstructed the pressure switch stops the gas 
supply by closing the gas valve. 
-  Gas valve: in the case that one of the safety devices is activated (limit thermostat, safety 
thermostat etc.) the gas valve is automatically de-energised with contemporary cut-off the 
burner’s gas supply. 
-  Electrical supply: 230 V – 50 Hz 
-  Operational temperature: 0°C to + 60°C 
-  Model:    HONEYWELL VK 4125A for the Heaters F1 21. 31. 41. 51. 61 
      BM 762 for the Heater Model F1 81 
-  Ignition and flame control box: controls the ignition and flame of the premix burner; if the is 
flame not detected during the safety period the flame control box will stop the appliance; with 
manual reset. 
-  Safety time: ignition 10 seconds 
-  Purge time: 40 seconds 
-  Power supply: 230V – 50 Hz 
-  Flame control box model: BRAHMA CM32PR 
-  Ignition transformer: BRAHMA TC2LTCAF / EICHHOFF 4718/2 
A
) flame control box 
B) pressure switch 
C) fuse 6,3A 5x20 
B
A
E
C
D
D) speed regulation board 
E) ignition transformer 
Figure 1 










